Final answer:
The power supply unit in a computer is responsible for providing surge suppression and power conditioning in addition to distributing power to other components.
Step-by-step explanation:
In addition to battery-supplied power, every power supply unit has surge suppression and power conditioning. The correct answer here is b) Power supply unit.
Power supply units (PSU) are crucial components in a computer that not only provide power to the motherboard, CPU, hard drives, and other components but also protect against power surges with surge suppression. Moreover, they ensure the delivery of clean power, free from voltage spikes or drops, through power conditioning.