I enjoy . . . . . . . . tennis. A. to playing B. playing C. plays D. to play

to playing
playing
plays
to play

The correct answer is B. playing.

The sentence “I enjoy playing tennis” is in the present simple tense. In the present simple tense, we use the -ing form of the verb to talk about things that we do regularly or habitually. In this case, the speaker is saying that they enjoy playing tennis on a regular basis.

The other options are incorrect because they are not in the -ing form. Option A, to playing, is the infinitive form of the verb. Option C, plays, is the third person singular form of the verb. Option D, to play, is the infinitive form of the verb followed by the preposition to.

In conclusion, the correct answer is B. playing.