The correct answer is A.
OBJ-2.5: An uninterruptible power supply or uninterruptible power source (UPS) is an electrical apparatus that provides emergency power to a load when the input power source becomes too low or the main power fails. A UPS provides near-instantaneous protection from input power interruptions by using a battery backup. The on-battery run-time of most uninterruptible power sources is usually short (less than 60 minutes) but sufficient to properly shut down a computer system. A line conditioner is a device that adjusts voltages in under-voltage and overvoltage conditions to maintain a 120 V output. Line conditioners raise a sag or under-voltage event back to normal levels, but they cannot protect the line from a complete power failure or power outage. A surge protector defends against possible voltage spikes that could damage your electronics, appliances, or equipment. A power strip will not protect against voltage spikes. A UPS or line conditioner could protect against voltage spikes, but they cost much more than a surge protector. A power distribution unit (PDU) is a device designed to provide power to devices that require power, and may or may not support remote monitoring and access.