The correct answer is C. haifi. The question is asking which word is the verb (aikatau) in the sentence. In the sentence "Wata akuya baka ta haifi tagwaye", "haifi" is the verb meaning "gave birth" or "had", while the other options - akuya (goat), baka (your), tagwaye (twins), and wata (a/she) - are all nouns or pronouns. Therefore, the correct answer is C. haifi, as it is the verb describing the action in the sentence.