Which prefix generally means again or back?

• A. Re-
• B. Un-
• C. Pre-
• D. Dis-

Answer: (A)

A prefix that means again or back attaches to a base word to show repetition or movement toward a previous state. That is why re- is the best fit: it signals doing something again, as in redo (do again), rewrite (write again), reopen (open again), or reuse (use again). The sense of returning to a prior action or state is common with re- across many words.

Other prefixes have different jobs. Un- expresses negation or the opposite of something (unhappy means not happy). Pre- indicates before in time or order (preheat, preview). Dis- often marks negation or separation (disagree, disconnect). They don’t convey repetition or returning to a prior act the way re- does.