Relationship Problem

Step 1: Breakdown

• "His father's wife" = Rohit's mother.
• "The only brother of his father's wife" = Rohit's maternal uncle.
• "The son of the only brother of his father's wife" = son of Rohit's maternal uncle.

Step 2: Conclusion

The son of Rohit's maternal uncle is Rohit's cousin.

Answer: (C) Cousin