Select the correct answer to fill in the blank: I am sure I ________ him before.

Correct answer: have met

Explanation: This is a case of Present Perfect Tense. We use have/has + past participle to talk about an action that happened at some unspecified time in the past but is still connected to the present. A. have met ✅ – correct; shows the speaker is certain about meeting him at some time before now (connection with present). B. met ❌ – simple past, refers to a definite time in the past (not used here since no specific time is given). C. had met ❌ – past perfect, used when referring to two past actions (not needed here). D. will meet ❌ – refers to future, not suitable here. ✔️ Correct sentence: I am sure I have met him before. ✅