. . . . . . . . you work very hard, you cannot pass?

A. Unless

B. Until

C. While

D. As if

Answer: Option A

Solution(By Examveda Team)

We use the conjunction unless to mean 'except if'. The clause which follows unless is a subordinate clause (sc): it needs a main clause (mc) to make a complete sentence. When unless comes before the main clause, we use a comma.