Pointing to a man, Asha said, “The only sister of his son is my daughter-in-law.” Asha has only one son. How is Asha’s son related to the man?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Son-in-law
A brother and a sister have the same father. A daughter-in-law is the wife of one’s son, and the husband of one’s daughter is one’s son-in-law.
The man’s son and the son’s sister have the same father, so the son’s only sister is the man’s daughter
This daughter is Asha’s daughter-in-law, so she is the wife of Asha’s son
Asha has only one son, so that son is the husband of the man’s daughter: he is the man’s son-in-law

Why the other options are incorrect
Option (1) Son — Incorrect. Asha’s son is the husband of the man’s daughter, not her brother.
Option (2) Brother-in-law — Incorrect. A brother-in-law is a wife’s brother or a sister’s husband; Asha’s son is the husband of the man’s daughter.
Option (3) Nephew — Incorrect. Asha’s son is not the son of the man’s brother or sister; he is married to the man’s daughter.