Air and fuel intake, compression and ignition, combustion and expansion, and exhaust are sequential steps in:

a. the four-stroke engine cycle.
b. compression reactions.
c. activation energies.
d. fossil fuels.
.

The sequence given above are sequential steps which usually take place in THE FOUR STROKE ENGINE CYCLE. The correct option is A. The four stroke cycle engine is an internal combustion engine which used four piston stroke to complete one operation cycle. The first step, which is intake stroke takes air and fuel into the combustion chamber. The second step, which is the compression stroke compresses the mixture into a smaller volume. In the third step [ expansion stroke], the fuel is ignited by the spark and in the fourth step [exhaust stroke], left over gases are pushed out through the exhaust pipe.