Answer: A) Son-in-law Explanation: Given that If Theresa's daughter is my daughter's mother It has 2 ways of Answers such that it depends on the sex of me. That is Male or Female.   1) If I am a Male : My daughter's mother is my wife. My wife is Teresa's daughter => I am Teresa's Son-in-law.   2) If I am a Female : My daughter's mother is myself. Myself Teresa's daughter. => I am Teresa's Daughter.   But in the given options only Son-in-law is available and daughter is not given.   So, Son-in-law is correct.