The rate of pressure rise during the period following fuel ignition in a diesel will result in （）

A.greater overall efficiency
B.greater fuel economy
C.lower horsepower
D.lower compression ratio

A.blows out the exhaust gases
B.supplies oxygen for combustion
C.cools the valves and cylinder walls
D.all of the above

A.delivering more air into the cylinder than it would normally receive during an ordinary charging process
B.forcing the products of combustion out of the cylinder with the fresh air charge
C.collecting the air charge at the cleaner
D.combustion and expansion of hot gas