In a single acting steam engine

A. The steam is admitted on one side of the piston and one working stroke is produced during each revolution of the crankshaft

B. The steam is admitted, in turn, on both sides of the piston and one working stroke is produced during each revolution of the crankshaft

C. The steam is admitted on one side of the piston and two working strokes are produced during each revolution of the crankshaft

D. The steam is admitted, in turn, on both sides of the piston and two working strokes are produced during each revolution of the crankshaft