Why FET stands for Field Effect Transistor. Unlike a bipolar transistor, which is controlled by current into its base, an FET is controlled by the voltage (electric field) applied to its gate, which widens or pinches off the conducting channel between source and drain. That voltage control means an FET gate draws almost no current, giving it very high input impedance.
Watch out The choices containing 'Transmitter' are a giveaway that they are wrong: an FET is a device inside a circuit, not a transmitter. 'Fast Electron Transistor' is not a real term.
F-E-T: Field Effect Transistor. Voltage at the gate makes the field; current flows source to drain.