Answer:
C. Silicon diode
Explanation:
A silicon diode is an example of a solid-state device. Solid-state electronics involve the use of semiconductor materials, such as silicon, to create devices like diodes, transistors, and integrated circuits. In contrast, vacuum tubes (option D) are not solid-state devices; they are based on the flow of electrons in a vacuum within the tube. Cermet resistor (option A) and tantalum capacitor (option B) are passive electronic components and are not considered solid-state devices.
