Explanation
tracert is a command-line tool that can trace the route of a packet from the source to the destination. It can show the number of hops, the IP address and hostname of each router, and the round-trip time for each hop.
tracert can help the technician troubleshoot the unreachable website by identifying where the packet is dropped or delayed along the path. ipconfig is a command-line tool that can display and configure the IP settings of a network interface. arp is a command-line tool that can display and manipulate the Address Resolution Protocol (ARP) cache, which maps IP addresses to MAC addresses. netstat is a command-line tool that can display network connections, routing tables, and statistics.
References: CompTIA Network+ Certification Exam Objectives Version 7.0 (N10-007), Objective 2.4: Given a scenario, use appropriate software tools to troubleshoot connectivity issues.

Explanation
A client-to-site VPN and a split-tunnel VPN are the best options for designing a secure remote access scheme that meets the given requirements. A client-to-site VPN allows users at multiple locations to access corporate resources over the internet by creating a secure tunnel between their devices and a VPN concentrator on the corporate network1. A split-tunnel VPN allows the on-premises equipment to handle only the traffic that is destined for the corporate resources, while the non-corporate traffic is routed directly to the internet without passing through the VPN tunnel2. This reduces the bandwidth and processing load on the corporate network and improves the performance of the remote access.
References:
Remote Access - N10-008 CompTIA Network+ : 4.41
comptia Network+ : Remote Access Methods And Network Monitoring2

Fiber is the best cable choice for long distances, as it can transmit data over 1,640ft (500m) without significant signal loss or interference. Fiber is also immune to electromagnetic interference and can support higher bandwidths than copper cables. Cat 5e and Cat 6a are copper cables that have a maximum distance of 328ft (100m) for Ethernet networks. Coaxial cable is also a copper cable that can reach longer distances, but it is mainly used for cable TV and not for Ethernet networks.

Port mirroring is a feature that can be used to enable monitoring of all packets arriving at an interface. This feature is used to direct a copy of all traffic passing through the switch to a monitoring device, such as a network analyzer. This allows the switch to be monitored with the network analyzer in order to identify any malicious or suspicious activity. Additionally, port mirroring can be used to troubleshoot network issues, such as latency or poor performance.