What is a variational optimizer responsible for?

Question: In a hybrid variational quantum algorithm, what does the classical optimizer do? A) Physically cool the quantum processor B) Delete the quantum circuit after each shot C) Update circuit parameters to improve the objective value D) Replace qubits with normal bits Correct: C Explanation: In variational algorithms, the quantum circuit evaluates an objective, while the classical optimizer updates parameters to reduce cost or improve performance. Topic: quantum computing / variational algorithms / optimization