Which of the following is a required component for making a bomb?

The identification of a power supply as a required component for making a bomb reflects an understanding of how explosive devices are activated. In many bomb designs, a power supply is essential to provide the necessary energy for detonation. It can be a battery or other source that powers the triggering mechanism, such as an electric fuse, which ignites the explosive materials.

When considering the other options, while a timer, pressure cooker, and fuze are often components found in specific bomb designs, they are not universally required for all explosive devices. For instance, a bomb could be triggered by a different means, such as remote detonation or pressure activation, which may not involve a timer. Similarly, while pressure cookers can be used in some improvised explosive devices due to their ability to contain and build pressure, they are not a fundamental requirement for all bombs. The fuze is certainly critical for initiating the explosion, but it is typically activated through a power source. Therefore, while other items can be part of a bomb's assembly, the power supply is essential across various designs as it is directly involved in the detonation process.