Conjunctions are words that link other words, phrases, or clauses together. Coordinating conjunctions allow you to join words, phrases, and clauses of equal grammatical rank in a sentence. The most common coordinating conjunctions are for, and, nor, but, or, yet, and so. Correlative conjunctions are pairs of conjunctions that work together. Some examples are either/or, neither/nor, and not only/but also. Subordinating conjunctions join independent and dependent clauses. Subordinating conjunction can signal a cause-and-effect relationship, a contrast, or some other kind of relationship between the clauses. Common subordinating conjunctions are because, since, as, although, though, while, and whereas. The given sentence requires the use of correlative conjunction in order to join subjects carrying equal weight in the sentence i.e.Ajay and Vijay. 'Both' refers to the whole pair and is equivalent to "one and the other". The combination both/and indicates that the two items are equally presented and included. Hence Option C is correct. Option A can be ruled out as 'or' indicates that there is a choice and only one can be selected while in the sentence 'both' has been inferred. Option B is ruled out as well. Since 'nor' is usually used with 'neither' in order to indicate that neither of the two choices can be selected. In other words, neither choice is available, the option is discarded. Option D is incorrect as a correct option is already present.