Elasticity is the ability of a system (often in cloud environments) to automatically scale resources up or down in real time based on demand.
A). Scalability means the ability to grow over time but not necessarily dynamically.
B). SaaS is a service model, not a resource-allocation concept.
C). Hybrid cloud is a deployment model, not a performance behavior.
References (CompTIA Network+ N10-009):
Domain: Networking Concepts - Cloud computing, elasticity vs. scalability.

VLAN hopping is an attack where an attacker crafts packets with multiple VLAN tags, allowing them to traverse VLAN boundaries improperly. This can result in gaining unauthorized access to network segments that are supposed to be isolated. The other options do not involve the use of multiple network tags. MAC flooding aims to overwhelm a switch's MAC address table, DNS spoofing involves forging DNS responses, and ARP poisoning involves sending fake ARP messages.
Reference:
According to the CompTIA Network+ course materials, VLAN hopping exploits the tagging mechanism in network packets to gain unauthorized access.

When a new VLAN is created, it typically exists on a different subnet. If DHCP servers are on a different VLAN, the network needs an IP helper address to forward DHCP requests correctly. Without it, clients in the new VLAN won't receive an IP address.
Breakdown of Options:
A: Scope size - Increasing the DHCP scope would not resolve the issue if requests aren't reaching the server.
B: Address reservations - Reservations only assign specific addresses to devices; they do not fix DHCP communication issues.
C: Lease time - Changing the lease time does not impact DHCP functionality across VLANs.
D: IP helper - Correct answer. This forwards DHCP requests across VLANs to the DHCP server.
Reference:
CompTIA Network+ (N10-009) Official Study Guide - Domain 2.4: Explain IP addressing technologies and subnetting.
RFC 1542: BOOTP (Bootstrap Protocol) relay agents

A SIEM (Security Information and Event Management) platform is built to collect, correlate, and alert on security-relevant events across many sources, which is exactly what's needed to identify patterns such as brute force attempts, port scanning, and DDoS indicators. In Network+ (N10-009) security operations concepts, correlation is key: a SIEM can ingest logs from firewalls, IDS/IPS, servers, authentication systems, endpoint agents, and network devices, then apply rules/analytics to detect suspicious behavior that might not be obvious from a single log source. It can also generate real-time alerts, dashboards, and incident timelines-helping the engineer respond quickly and prioritize threats.
Packet capture provides deep visibility into traffic but is not inherently designed for enterprise-wide correlation and alerting without significant additional tooling and expertise. SNMPv3 is used for secure device monitoring (status, counters, performance) rather than detecting coordinated attack patterns. A syslog collector centralizes logs but generally does not provide the same level of correlation, enrichment, and automated alerting capabilities as a SIEM. Therefore, SIEM is the best answer.

RPO (Recovery Point Objective) describes a data recovery goal by defining the maximum acceptable amount of data loss measured in time. For example, an RPO of 4 hours means the organization must be able to restore data to a point no more than four hours before the outage-so backups, replication, or snapshots must occur frequently enough to meet that target. In Network+ (N10-009) operations objectives, disaster recovery and business continuity concepts include understanding recovery metrics and how they influence backup strategies, replication design, and service resilience planning. RPO specifically answers: "How much data can we afford to lose?" By contrast, MTBF (Mean Time Between Failures) is a reliability metric describing how often failures occur. MTTR (Mean Time To Repair/Recover) measures how long it takes to restore a system after failure, which is more aligned with service restoration time rather than data loss. BCP (Business Continuity Plan) is the overall plan/process for keeping critical business functions running during disruptions; it is not a single data recovery metric. Therefore, RPO is the correct term for a data recovery goal.