正解:A
A UPS (Uninterruptible Power Supply) and PDU (Power Distribution Unit) are installed to provide reliable, properly distributed electrical power to network equipment-especially in wiring closets such as an IDF and in main equipment rooms. In Network+ (N10-009) infrastructure objectives, a UPS protects against power loss and instability by supplying battery-backed power during outages and often providing conditioning to reduce the impact of sags, spikes, and brief interruptions. A PDU then distributes that power to multiple devices in a rack (switches, routers, firewalls, AP controllers), often offering organized outlets and, in managed models, monitoring/control features.
Option A is the best match because it reflects the practical purpose: ensuring network devices receive appropriate and continuous power in distribution frames/closets. Option B is partially related, but "managing power consumption in the MDF" is too narrow and not as accurate as the broader function of providing backup and distribution power. Option C describes a network switch, not power equipment. Option D refers to HVAC/environmental controls, not UPS/PDU functionality. Hence, A is correct.