The behavior and operation of the MOSFET are largely based on the physics of the MOS capacitor. Initially, we will ignore the presence of the source and drain. Now, let's create a complete question with four options: How is the behavior and operation of the MOSFET primarily determined?

A) By the physics of the MOS capacitor
B) By the presence of the source and drain
C) By the size of the MOSFET
D) By the voltage applied to the gate