If Kamal says, "Ravi`s mother is the only daughter of my mother", how is Kamal related to Ravi ?

A. NONE OF THESE

A is the brother of B. B is the brother of C. D is the father of A. Based on these three satatements, which of the following statements cannot be definitely true ?

D. C IS THE BROTHER OF A.

Pointing to a man on the stage, Rita said, "He is the brother of the daughter of the wife of my husband."
How is the man on the stage related to Rita ?

A. SON

C is A's father's nephew. D is A's cousin but not the brother of C.
How is D related to C ?

B. SISTER

All the six members of a family A, B, C, D, E and F are travelling together. B is the son of C but C is not the mother of B, A and C are a married couple. E is the brother of C. D is the daughter of A. F is the brother of B. How is E related to D ?

C. UNCLE