There are actually TWO correct answers given in this question; which are the third AND fourth answer choices:
___________________
Answer choice 3:
________________________
"There's nothing we like better than to relax, watch movies, and hang out."
________________________
Answer choice 4:
___________________
"When you make friends, you should stay in touch, smile and be nice."
___________________
Let us review the answer choices.
____________________
Consider the first answer choice:
_________
"It is important to study, staying on top of your homework, and go to class."
________
This answer choice does NOT use parallel structure. To make this answer choice use parallel structure, we would need the sentence to:
________
"It is important to study, stay on top of your homework, and go to class." ; OR:
__________
"Studying, staying on top of your homework, and going to class are important."
____________
Let us examine the second answer choice given:
___________________
"My three favorite activities are writing, reading, and go to the library."
_________
This answer choice does NOT use parallel structure. To make this answer choice use parallel structure, we would have to rewrite the sentence as:
_________
"My three favorite activities are writing, reading, and going to the library."
________