The boys are . . . . . . . . their home task?

The correct answer is Option A: doing

The verb “are” requires a present participle (verb+ing) to form the present continuous tense.

In the sentence, the action is happening currently, so the correct structure is “are doing.”

Options “do” and “does” are simple present forms and grammatically incorrect here.

“Going to do” expresses future intention, which does not fit the sentence meaning.