What does the Estimator primitive compute?

Question: In Qiskit-style workflows, what is the Estimator primitive mainly used to compute? A) Raw bitstring counts only B) The shortest path in the coupling map C) Expectation values of observables for quantum circuits D) The number of qubits required for refrigeration Correct: C Explanation: The Estimator evaluates expectation values of observables with respect to states prepared by quantum circuits. This makes it useful for algorithms such as VQE, QAOA, and chemistry simulations. Topic: quantum computing / Qiskit / Estimator