Which of the following is key reason to include hyperbole in a literary work?

i. to add humor
ii. to heighten effect
iii. to create suspense

I believe that there are two key reasons to include hyperbole in a literary work - one of them is to heighten an effect, and the other one is to add humor. Therefore, I'd say the correct answer is I and II. Hyperbole is exaggeration - writers often use this figure of speech in order to mock somebody by exaggerating their features in order to ridicule them.