What does circuit depth mean?

Question: What does circuit depth usually represent? A) The number of qubits in a quantum processor B) The number of layers of operations that must be executed sequentially C) The size of the classical output register only D) The probability of measuring zero Correct: B Explanation: Circuit depth measures how many layers of gates must be performed in sequence. Lower depth is often preferred on noisy hardware because long circuits are more exposed to decoherence and gate errors. Topic: quantum computing / circuit depth