The most commonly used semiconductor in the manufacture of a transistor is ___________

germanium
silicon
carbon
none of the above

The correct answer is B. silicon.

Germanium was the first semiconductor used in transistors, but it was soon replaced by silicon because it is more stable and has a higher resistance to heat. Silicon is also more abundant than germanium, which makes it cheaper to produce.

Carbon is not a semiconductor. It is a conductor of electricity.

The other options are incorrect.