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 B — slip joint

In floating offshore drilling units, a slip joint (or telescopic joint) permits relative vertical motion between the floating vessel and the fixed marine riser. This compensates for heave caused by wave action, preventing over-tensioning or buckling of the riser string under dynamic sea conditions.