'c' wave of JVP: (A) Occurs during rapid filling phase of cardiac cycle, (B) Occurs due to opening of tricuspid valve, (C) Occurs due to closure of tricuspid valve into right atrium, (D) Occurs at the end of T wave
Answer is C. c' wave of JVP

Occurs due to bulging of tricuspid valve into right atrium
Occurs during isovolumetric contraction phase
In tricuspid regurgitation, v wave merge with c wave.