When used with reversing reduction gears, medium-speed diesel engines should be bolted to their foundations with fitted bolts at the drive end and clearance(loosely fitted) bolts in other locations √This is done to （）

A. maintain alignment when the ship’s hull is working in heavy seas
B. ensure engine vibrations correspond to the natural frequency of the hull
C. permit the engine to expand away from the driven equipment as the engine heats up and expands
D. maintain engine thrust bearing clearance