A is the brother of B. C is the father of A. D is the brother of C. E is the son of D. How is E related to B?

Correct — A.
Rule: the child of a parent's brother is a cousin.

A is B's brother and C is A's father, so C is B's father too.
D is C's brother, so D is B's paternal uncle.
E is D's son, so E is B's uncle's son: B's cousin → option (a).

Why the others are wrong

• (b)
  Nephew — A nephew is a sibling's son, one generation below B. E is the son of B's uncle, so he stands in B's own generation.
• (c)
  Uncle — Uncle is D's relation to B, not E's. E is D's son, one generation below D and level with B.
• (d)
  Brother-in-law — Brother-in-law needs a marriage, and the stem mentions none. E is linked to B only by blood, through the brothers C and D.

Blood-relation chains are solved one link at a time. Hang every person on one family tree and track the generation.

C and D are brothers in the upper generation. A and B are C's children, and E is D's child. Children of two brothers are first cousins, whatever their gender.

B's gender is never stated, and it does not matter: cousin is the same word for a male or a female.

Key facts

• Siblings share parents, so A's father C is also B's father.
• A father's brother is a paternal uncle.
• The children of two brothers are cousins.

Common traps

• Answering with D's relation to B (Uncle) instead of E's.
• Stalling because B's gender is not given, though cousin does not depend on it.

No directly related past PYQ was found.