What is a quantum oracle?

Question: In many quantum algorithms, what is an oracle? A) A hardware chip that cools the quantum computer B) A black-box operation that marks or encodes information about a solution C) A measurement result stored after every shot D) A classical sorting algorithm Correct: B Explanation: An oracle is a special operation used in algorithms such as Grover's algorithm. It marks the desired solution state so that later interference steps can amplify it. Topic: quantum computing / oracle / Grover