The correct answer is A. Donor doped.
A nMOSFET (n-channel metal-oxide-semiconductor field-effect transistor) is a type of transistor that uses an n-type semiconductor material as its channel. The channel is doped with donor impurities, which give it an excess of electrons. When a voltage is applied to the gate, it creates an electric field that attracts the electrons in the channel, causing them to flow through the device. This flow of electrons is what allows the nMOSFET to function as a switch or amplifier.
A pMOSFET (p-channel metal-oxide-semiconductor field-effect transistor) is a type of transistor that uses a p-type semiconductor material as its channel. The channel is doped with acceptor impurities, which give it a deficiency of electrons. When a voltage is applied to the gate, it creates an electric field that repels the electrons in the channel, causing them to flow through the device. This flow of holes is what allows the pMOSFET to function as a switch or amplifier.
In conclusion, nMOSFETs are donor doped, while pMOSFETs are acceptor doped.