Based on the family photo album described, Mamta is Vijay’s:
Meera shows her friend a family photo album. Pointing to a boy, she says, "This is Dakshit and he is my grandfather's only grandson." Later, she shows the photos of her grandfather's two sons, Jayesh and Vijay, and tells her that her grandfather has only two sons and no daughters. Pointing to a woman, she says, "This is my mother Sheetal, who is standing with her brother-in-law Vijay and his wife Sunita." Meera also shows the photo of her only sister Mamta.
Correct answer: D
Explanation
Mamta is Meera's only sister, so both are daughters of Jayesh and Sheetal. Vijay is Jayesh's brother, which makes him Mamta's uncle. Mamta is therefore Vijay's niece.