Answer:
D. peace.
Step-by-step explanation:
After Catherine dies, Heathcliff is very disturbed and more cruel and sickly than before. Besides, Catherine's spirit is haunting Heathcliff making him even more annoyed, upset, and vindictive. What Heathcliff wants most in life is to find Catherine, because only then will he find the peace that is lacking in his life, but Catherine is dead and the only way Heathcliff finds her is dying as well. When Heathcliff passes away, he finds peace through reunion with Catherine.