A is B’s brother. C is A’s mother. D is C’s father. E is B’s son.
We will draw the flow chart of given information as follows, circle around the alphabet indicates that that person is a lady.
In the information it is not clearly mentioned whether B is a male or female. So the B is either the grandson or grand daughter of D. But in option grand-son is not given so we will consider B as a female and so answer is grand daughter. So b is the answer.