What’s . . . . . . . . name of that man we met yesterday? A. a B. an C. the D. no article

The correct answer is: D. no article

The article “a” or “an” is used before a singular noun that refers to a general or unspecified person or thing. In this case, the man we met yesterday is a specific person, so we do not use an article.

The article “the” is used before a singular noun that refers to a specific person or thing that has already been mentioned or identified. In this case, the man we met yesterday has not been mentioned or identified, so we do not use the article “the.”

No article is used before a singular noun that refers to a general or unspecified person or thing. In this case, the man we met yesterday is a specific person, so we do not use an article.