Step 1: Understanding the Legal Restrictions on Marriages.
Under Hindu Marriage Act, marriages between close blood relatives such as between an uncle and niece are prohibited. In this case, the marriage between Mohan and his sister's daughter (niece) is void as per the law.
Step 2: Explanation of Other Options.
- (a) Even if the custom allows it, the law prohibits such marriages.
- (c) Court approval does not legalize a prohibited marriage.
- (d) The Panchayat does not have the authority to validate a marriage between close relatives.
Step 3: Conclusion.
This marriage is void as it is between prohibited blood relations.