|A) Brother||B) Son-in-Law|
|C) Brother-in-Law||D) None of these|
A is a male and married to B. So, A is the husband and B is the wife. C is the brother of A. D is the son of C. E, who is the sister of D will be the daughter of C. B is the daughter-in-law of F whose husband has died means F is the mother of A.
C is the brother of A who is the husband of B. So, C is the brother-in-law of B