Answer: NAND.
- A AND
- B OR
- C NOT
- D NAND
Correct answer: D. NAND
Explanation: NAND (and NOR) are universal gates: any logic function can be built using only NAND gates.
Conductors have overlapping bands, semiconductors have a small energy gap that can be bridged by heat or doping, and insulators have a large gap that blocks conduction.
Concept context
Band theory, p-n junction, diodes, transistors, logic gates, and integrated circuits.