Topic: Fill in the Blank,

Best Answer Explained in Below-:

The correct answer is C: "will have begun" because it appropriately uses the future perfect tense, which indicates an action that will be completed before a specified point in the future.

In the given sentence, the context is that he will arrive quite late. The phrase "by the time he comes" sets a future reference point. We need to express an action (the pay beginning) that will have already occurred by that time in the future.

The structure of the future perfect tense is "will have" followed by the past participle of the verb. In this case, the verb is "begin," and its past participle form is "begun." Therefore, "will have begun" suggests that the pay process will already be underway by the time he arrives.

Options A ("would have begun") and B ("would begun") are inappropriate for this context because they imply a hypothetical situation and do not follow the correct tense structure, respectively. Option D ("will begun") is also incorrect due to the misuse of the verb form. Thus, "will have begun" is the only option that conveys the intended meaning clearly and correctly.