The transceivers that the architect should recommend for each pair of switches are two QSPF+ MPO. This option would provide 40 Gbps bandwidth per link, which is enough to meet the customer requirement of 80 Gbps for the link aggregation. The QSPF+ MPO transceivers use a single multi-fiber connector that can support up to 12 fibers, which is compatible with the customer's existing OM4 multi-mode fiber infrastructure.
The QSPF+ MPO transceivers also support distances up to 100 meters, which is sufficient for the customer's inter-building connections.
The other options are not optimal for the customer requirement because they either provide insufficient bandwidth or require additional fiber strands. Two QSPF+ BiDi transceivers would provide only 20 Gbps bandwidth per link, which is half of the customer requirement. Eight SFP+ LR or SR transceivers would provide 80 Gbps bandwidth per link, which is more than the customer requirement, but they would also require eight fiber strands per link, which is more than the customer's available fiber infrastructure.
References:
Aruba Transceiver and Cable Data Sheet (Aruba Networks)
Designing Aruba Solutions Study Guide (HPE Press)

The correct answer is option C, 20-25. This is because a general rule of thumb for 802.11ac wireless deployment is to have one AP for every 200 square meters (approximately 2,000 square feet) of coverage area.
This assumes a moderate user density and application demand. Therefore, for a coverage area of 4,645 square meters (approximately 50,000 square feet), the architect should have in mind about 23 APs (4,645 / 200 =
23.225). This number can be adjusted based on the actual site survey and VisualRF plan, but it serves as a good starting point. References: The information can be referenced from the official HPE documents and learning materials available on HPE Press and Aruba Networks. Specifically, it aligns with the objectives outlined in Chapter 4: Wireless LAN Design, where the AP count estimation and site survey methods are discussed. Designing Aruba Solutions Official Certification Study Guide Aruba Mobility Fundamentals Guide

The correct answer is option C, voice. Voice applications have the greatest potential impact on RF design because they are sensitive to latency, jitter, and packet loss. Voice applications also require a minimum signal strength and signal-to-noise ratio to ensure good voice quality. Therefore, an architect needs to consider the number of voice devices, the codec used, the roaming behavior, and the call admission control when planning the RF coverage for voice applications. References: The information can be referenced from the official HPE documents and learning materials available on HPE Press and Aruba Networks. Specifically, it aligns with the objectives outlined in Chapter 3: Wireless LAN Technologies and Standards, where the RF design considerations for voice applications are discussed. Designing Aruba Solutions Official Certification Study Guide Aruba Mobility Fundamentals Guide