The correct answer is B. read.
The sentence “I have read the two books” is in the simple past tense. The simple past tense is used to talk about actions that happened in the past and are now finished. In this case, the speaker is saying that they have finished reading the two books.
The other options are incorrect because they do not agree with the tense of the sentence. Option A, “reading”, is in the present participle tense. The present participle tense is used to talk about actions that are happening now or that happen repeatedly. Option C, “none”, is not a verb. Option D, “been reading”, is in the present perfect progressive tense. The present perfect progressive tense is used to talk about actions that started in the past and continue to happen in the present.
Here are some examples of how the other options could be used in a sentence:
- I am reading the two books. (present tense)
- I have read the two books before. (simple past tense)
- I have been reading the two books for hours. (present perfect progressive tense)