Final answer:
The pronoun 'himself' in the sentence is a reflexive pronoun, referring back to 'my brother', the subject of the sentence. Option A is correct.
Step-by-step explanation:
The correct type of pronoun used in the sentence 'For his birthday, my brother bought himself a new cell phone' is A. reflexive. Reflexive pronouns are used to refer back to the subject of the sentence.
In this case, 'my brother' is the subject, and 'himself' is the reflexive pronoun that refers back to 'my brother'. Reflexive pronouns are easily identifiable as they end in '-self' or '-selves'.
They are essential when the action of the verb refers back to the doer, which is 'my brother' in the given sentence.
Hence, A reflexive pronoun is used when the subject and object of a sentence refer to the same person or thing. In the sentence 'For his birthday, my brother bought himself a new cell phone,' the pronoun 'himself' refers back to the subject 'my brother.' Option A is correct.