Pistons may be made in （） in order to keep the weight down for balancing purposes at high speed.

A.lifted
B.reassembled
C.dismounted
D.disassembled

A.a low load on that cylinder
B.sluggish piston ring action
C.excessive piston crown cooling
D.excessive clearance of piston pin

A.the same as
B.similar to
C.separated from
D.different from