What does the distance of a quantum code determine?

Question: For a quantum code of distance d, which generic error-correction capability is guaranteed? A) It can correct any error acting on at most floor((d−1)/2) physical qubits and detect errors of weight below d B) It corrects every Pauli error of weight at most d, but detects only errors below d/2 C) It corrects exactly d−1 erasures but no unknown Pauli errors D) It corrects floor(d/2) arbitrary errors whenever syndrome measurements are noiseless Correct: A Explanation: Code distance is the minimum weight of a nontrivial logical operator. Consequently, errors affecting fewer than d qubits are detectable, while arbitrary errors on up to floor((d−1)/2) qubits are correctable. Topic: advanced quantum computing / quantum error correction / code distance