Correct answer: D). Diodes, which are often utilized as rectifiers, have two electrodes.
A diode has two electrodes named as anode and cathode. Electrons are being discharged in the cathode-anode which attracts each other when the voltage is applied.through it. Triode has three electrodes which include grid, anode and cathode. Grid and the cathode offset voltages with a minute variation of input.
Hence, the correct answer would be option D.