25. For a diesel engine an initial downward stroke of the piston draws in the air to charge thecylinder, which is followed by the compression stroke, with the fuel being injected as top dead center is approached, then a downward power stroke, and an upward exhaust stroke. Which type of engine is called for this operation?
(A) Two-stroke engine
(B) Four-stroke engine
(C) Supercharging engine
(D) Ideal cycle engine