Answer:
C. Moreover
Explanation:
Adverbs are words we use to modify (describe) verbs, adjectives, and other adverbs.
Conjunctive adverbs are adverbs used to connect two independent clauses. They're used to show a variety of relationships, such as sequence, contrast, cause and effect, etc. When it comes to punctuation, they are usually preceded by a semicolon and followed by a comma.
The conjunctive adverb used in the given sentence is moreover.