A network technician is planning a network scope means that the technician is defining the range of IP addresses that can be assigned to the devices on the network.
The web server needs to be within 12.31 69.1 to 12.31.69.29 means that the web server must have an IP address that falls within this range, which is a subset of the network scope.
A range reservation is a feature of DHCP that allows the technician to reserve a specific range of IP addresses for a certain type of device, such as a web server, and prevent other devices from using those addresses. This ensures that the web server will always have an IP address within the desired range and avoid IP conflicts with other devices.
A range reservation would meet this requirement, as the technician can configure the DHCP server to reserve the range of 12.31 69.1 to 12.31.69.29 for the web server and assign it an IP address from that range.
The other options are not correct because:
Lease time is the duration for which a DHCP server assigns an IP address to a device, not a way to specify a range of IP addresses.
DNS is a service that resolves domain names to IP addresses, not a way to define a network scope or reserve a range of IP addresses.
Superscope is a feature of DHCP that allows the technician to combine multiple scopes into one logical scope, not a way to restrict a range of IP addresses for a specific device.
Reference:
CompTIA Network+ N10-008 Certification Study Guide, Chapter 2: Network Implementations, Section 2.3: DHCP1 Professor Messer's CompTIA N10-008 Network+ Course Notes, Page 15: DHCP2 Professor Messer's CompTIA N10-008 Network+ Training Course, Video 2.3: DHCP3

A DHCP relay is a network device that forwards DHCP requests from clients on one subnet to a DHCP server on another subnet. This allows the DHCP server to assign IP addresses and other network configuration parameters to clients across different subnets. A DHCP scope is a range of IP addresses that a DHCP server can assign to clients. A DHCP snooping is a security feature that filters and validates DHCP messages on a switch. A DHCP reservation is a way to assign a specific IP address to a specific client based on its MAC address. Reference: Part 2 of the current page talks about DHCP relay and its functions. You can also find more information about DHCP relay on [this page].

The question asks about the most detailed source of data for investigating a network attack that wiped the configuration and logs of the border firewall.
The answer is not B, because the MIB (Management Information Base) of the attacked firewall is a database of network objects that can be monitored by a network management system, but it does not store historical data or logs of the firewall activity or configuration.
The answer is not C, because network baseline reports are snapshots of the normal performance and behavior of the network, but they do not provide specific details or evidence of the network attack or the firewall compromise.
The answer is not D, because NetFlow aggregate data is a collection of statistics about the network traffic flows, but it does not include the payload or content of the packets, which could be useful for identifying the attack vector or the malicious code.
The answer is A, because syslog server messages are records of the events and messages generated by the network devices, including the firewall. They can provide detailed information about the firewall configuration, status, errors, warnings, and alerts, as well as the source and destination of the network traffic. Syslog server messages can help to reconstruct the timeline and sequence of the network attack and the firewall compromise.
Reference:
1: CompTIA Network+ N10-008 Study Guide, Chapter 5: Network Management, Section 5.1: Network Monitoring, p. 271
2: CompTIA Network+ N10-008 Study Guide, Chapter 5: Network Management, Section 5.2: Network Performance Optimization, p. 282
3: CompTIA Network+ N10-008 Study Guide, Chapter 5: Network Management, Section 5.1: Network Monitoring, p. 274
4: CompTIA Network+ N10-008 Study Guide, Chapter 6: Network Security, Section 6.4: Network Security Monitoring and Analysis, p. 353

If a network client is trying to connect to the wrong TCP port, the most likely response it would receive is a RST (reset) packet from the server. A RST packet is used to terminate a TCP connection abruptly, either because the server does not recognize the port number, or because the server has no application listening on that port, or because the server detects an error or an attack on the connection. A RST packet tells the client to stop sending any more data and close the connection immediately12 The other options are not as likely to be the responses for connecting to the wrong TCP port. A FIN (finish) packet is used to gracefully end a TCP connection, after both parties have exchanged all the data they need. A FIN packet indicates that the sender has no more data to send and is ready to close the connection. A FIN packet does not imply an error or a rejection, but rather a normal termination of the connection12 An ICMP (Internet Control Message Protocol) Time Exceeded message is used to inform the sender that a packet has been discarded because its time to live (TTL) value has reached zero. A TTL value is a counter that decrements by one every time a packet passes through a router. When the TTL value reaches zero, the packet is dropped and an ICMP Time Exceeded message is sent back to the sender. This message is used to prevent packets from looping endlessly in the network, and also to implement the traceroute tool, which shows the path and the hops that a packet takes to reach a destination. An ICMP Time Exceeded message is not related to the TCP port number, but rather to the IP routing and the TTL value3 A Redirect message is another type of ICMP message that is used to inform the sender that there is a better route to the destination. A Redirect message is sent by a router when it receives a packet from a host on the same network, and forwards the packet to another router on the same network. A Redirect message tells the sender to use the second router as the next hop, instead of the first router, to optimize the routing and avoid unnecessary hops. A Redirect message is also not related to the TCP port number, but rather to the IP routing and the network topology3 Reference:
What causes a TCP/IP reset (RST) flag to be sent?
RFC 792: Internet Control Message Protocol

Bandwidth management is used to prioritize Internet usage per application and per user on the network. This allows an organization to allocate network resources to mission-critical applications and users, while limiting the bandwidth available to non-business-critical applications. Reference: Network+ Certification Study Guide, Chapter 2: Network Operations