You are correct, the answer is A) pitch. The pitch of a ship's propeller is the distance the ship would move forward in one complete revolution of the propeller if there was no slip. This is the theoretical or ideal distance the ship would move forward per revolution. The actual distance the ship moves forward per revolution, taking into account propeller slip, is called the advance. The other options are incorrect: B) head reach is the distance the ship moves forward during the time the rudder is being turned, C) advance is the actual distance moved per revolution accounting for slip, and D) transfer is the sideways movement of the ship during a turn.