The plot of Romeo and juliet reaches its climax when

A. Tybalt is killed

B. Mercutio is killed

C. Paris dies

D. Romeo and Juliet die

The main Climax was obviously when Romeo and Juliet die together*

So the answer is D

the entire story was leading up to their death and finally it came. Just as the audience expected, Since they read the beggining entry, where William summarizes the entire story. Accept the auidences jobs were to see how the story unfolds. Finally getting to the main part, where they die together in that grave.