The answer would be C. (Took the test and got it right)
Answer:
Since
So that
Than
Though
Unless
Until
Until
When
Whenever and many more...
Explanation:
Adverbial clauses, or adverb clauses, are groups of words that act as an adverb when used together. This means that the phrase gives more information or context about a verb, an adjective, or an adverb.