What is quantum interference?

Question: What is quantum interference used for in quantum algorithms? A) Amplifying desirable outcomes and reducing undesirable outcomes B) Copying unknown quantum states C) Making all measurements deterministic D) Turning qubits into classical bits without measurement Correct: A Explanation: Quantum interference occurs when probability amplitudes combine. Algorithms use interference so that amplitudes for wrong answers cancel out while amplitudes for useful answers become stronger. Topic: quantum computing / interference / algorithms