The correct answer is D because the SPAN session must capture only the traffic relevant to the two reported problems. For PC1, the diagram shows it is in VLAN 10, so using source vlan 10 rx focuses the capture on traffic received in that VLAN and avoids collecting unnecessary traffic from VLAN 15, which belongs to PC2. That makes option D more precise than option C, which would also mirror VLAN 15 traffic and add noise to the analyzer output.
For the server issue, the servers are behind SW2, which is connected to the Nexus on Ethernet 1/2. Therefore, the uplink toward SW2 must also be included as a source so the engineer can inspect traffic related to the packet drops affecting those servers. Cisco NX-OS SPAN supports mixing VLAN sources and interface sources in the same monitor session when the goal is targeted troubleshooting.
Options A and B mirror both switch uplinks only, which does not isolate PC1 specifically. Option C is too broad because it mirrors VLANs 10 through 15. Thus, D is the best configuration because it captures PC1's VLAN 10 traffic and the SW2 uplink traffic needed for investigation.