I’m afraid of . . . . . . . . dogs. A. a B. an C. the D. no article

The correct answer is D. no article.

The sentence “I’m afraid of dogs” is a general statement about dogs, not about a specific dog. Therefore, we do not need to use an article.

If we were to say “I’m afraid of the dog,” that would mean that we are afraid of a specific dog that we know.

If we were to say “I’m afraid of a dog,” that would mean that we are afraid of any dog, but we don’t know which dog specifically.

And if we were to say “I’m afraid of an dog,” that would be grammatically incorrect.

Therefore, the correct answer is D. no article.