Final answer:
d. Dhir Mal was the brother of Guru Har Rai Ji. Guru Har Rai Ji was the seventh Sikh Guru, and Guru Tegh Bahadur, also a Sikh leader, was executed by Aurangzeb.
Step-by-step explanation:
The brother of Guru Har Rai Ji is d. Dhir Mal. Guru Har Rai Ji was the seventh of the Sikh Gurus, and his brother did not succeed him as Guru. Instead, the leadership passed to Guru Har Rai Ji's son, Guru Har Krishan Ji.
Sikhism is the religion founded by Guru Nanak Dev Ji, and Guru Tegh Bahadur, who was executed by Aurangzeb, was also a leader of the Sikh faith, thereby answering the multiple-choice question with option a. Sikh.