Question

Which word is best related to the underlined word in the paragraph and how do the words relate?

Answer 1

I believe that the answer is B. Required
Definition of required: Needed.

Answer 2

Required.

These two terms are related because they both mean necessary, essential, or needed. Required means that it's plainly needed. Vital is more dramatic, more serious, and it means that without it, there is no function.

I hope it's right!