Answer:
Fourth Stroke.
Explanation:
There are four strokes in a car engine
a) Intake stroke: In this stroke the air and fuel is being pumped into the compressor from intake valve.
b) compression stroke: The piston moves upward and the fuel air mixture undergoes compression.
c)combustion stroke: The spark plug generates a spark and the fuel undergoes combustion. The energy produced push the piston backwards or downwards.
d) Exhaust stroke: the exhaust gases like carbon dioxide , water, carbon monoxide etc are forced up by the piston.
