Final answer:
The correct option is A. Oliver Cromwell's policies were related to the Commonwealth and Protectorate during the Interregnum period. He instituted religious toleration and governed as a Lord Protector until the Restoration of monarchy with Charles II.
Step-by-step explanation:
The policies Oliver Cromwell instituted were part of the governance during the Interregnum period after the English Civil War. The correct answer to the question 'What policies did Oliver Cromwell institute?' is A. The Commonwealth and Protectorate. During his rule, Cromwell upheld the English Commonwealth, a republic led by a Parliament, a Council of State, and a Lord Protector, which was Cromwell himself.
He supported religious toleration except for Catholics, as outlined in the Instrument of Government. Cromwell also showed a strong military leadership but faced struggles balancing the power between the army, nobility, Puritans, and Parliament. His policies set the stage for a brief period without monarchy until the Restoration of Charles II to the throne, which marked the end of the Commonwealth.