The element used to keep weight on the bit at a constant value in spite of up-and- down movement of a MODU during floating drilling operations is the heave or drill string __________.

Correct Answer: Option C — compensator

A drill string heave compensator is a hydraulic-pneumatic tensioning device used on floating Mobile Offshore Drilling Units (MODUs). It absorbs vertical vessel movement caused by ocean swells, maintaining a constant downward force (weight on bit) during floating drilling operations.