What is phase kickback?

Question: What is phase kickback in quantum computing? A) A process where measurement reverses a quantum circuit B) A phenomenon where a controlled operation transfers phase information back to the control register C) A method for deleting unused qubits D) A hardware cooling technique Correct: B Explanation: Phase kickback occurs when a controlled operation causes phase information from the target operation to appear on the control qubit or control register. It is important in several quantum algorithms. Topic: quantum computing / phase kickback