In comparison to exhaust valves, intake valves of diesel engines may be fabricated from low alloy steels because （）.

A.the beveled edges of the intake valves provide for serf-centering during seating
B.intake valves utilize stellite-coated valve seat inserts which reduce wear
C.the volume of air passing through intake valves is less than the volume of air passing through exhaust valves
D.intake valves are less affected to the corrosive action of exhaust gases