The joint of the riser in a marine riser system that compensates for heave, the up- and-down motion of a floater, is the __________.

Correct Answer: Option A — slip joint

A slip joint (or telescopic joint) is placed near the top of a marine riser system on a floating drilling unit. It expands and contracts telescopically to absorb the vessel's vertical heave motion relative to the seabed, preserving structural integrity of the riser pipe.