Which two components require thermal paste to be applied?

The correct answer identifies the CPU and Heat Sink as the two components that require thermal paste to be applied. Thermal paste is used between the CPU and the Heat Sink to ensure efficient heat transfer.

The CPU generates heat during operation, and the Heat Sink is responsible for dissipating this heat into the surrounding air. To maximize this heat dissipation, thermal paste fills the microscopic gaps between the CPU surface and the Heat Sink. Without it, air pockets can form, significantly limiting the effectiveness of the heat transfer and potentially leading to overheating of the CPU.

Other options do not require thermal paste. For example, the power supply does not come into direct contact with the CPU for heat transfer purposes, and neither does the motherboard utilize thermal paste in its assembly. Similarly, case fans do not interact with the CPU in a way that would necessitate thermal paste, as their role is to circulate air rather than directly cool the CPU through conduction. Thus, the application of thermal paste is specifically important for the CPU and Heat Sink connection in maintaining optimal operating temperatures.