Question

12. _______ conjunctions are found in pairs. A. Correlative B. Relative C. Subordinating D. Coordinating

Answer 1

The correct answer is A. correlative.
Correlative conjunctions are always found in pairs. These are conjunctions such as neither...nor, either...or, not only...but also, etc. 
There is no such things as a relative conjunction; subordinating and coordinating conjunctions don't come in pairs - subordinating are used for dependent clauses, and coordinating for relations between words/phrases and independent clauses.

Answer 2

The answer is correlative. Both...and, neither...nor, either...or, not only...but also.