What is a logical qubit?

Question: What is a logical qubit? A) A protected qubit encoded using multiple physical qubits B) A qubit that has already been measured C) A classical bit stored in RAM D) A qubit that cannot be used in algorithms Correct: A Explanation: A logical qubit is an error-protected unit of quantum information built from several physical qubits. This is used in quantum error correction to make computations more reliable. Topic: quantum computing / logical qubits / error correction