The best answer is B because it explains the operational impact of cable signal quality on the entire high-speed fabric. In NVIDIA AI clusters, InfiniBand and high-speed Ethernet links carry latency-sensitive GPU communication traffic for NCCL, RDMA, distributed training, storage access, and control-plane services. Poor signal quality increases bit error rates, which can lead to corrected errors, retransmissions, degraded throughput, congestion, timeouts, and unstable workload performance. NVIDIA cabling guidance explains that high-rate InfiniBand networks require excellent signal integrity and low BER, and NVIDIA Ethernet documentation notes that FEC helps detect and correct bit errors on high-speed links. However, FEC is not a substitute for poor cabling; excessive physical-layer errors still reduce performance and complicate troubleshooting. Option C is partially true because EMI and crosstalk can contribute to errors, but it is narrower than the full impact. Option D is also partially true, but it focuses only on FEC. Option A is incorrect because cable length, media type, connector type, and supported transceiver specifications remain critical in modern AI data center deployments.