Concept:Family tree relationships based on given connections.
Explanation:• C is wife of B, so B and C are a couple.
• E is son of C, so E is also son of B (since C and B are married). Thus E is child of B.
• A is brother of B, so A and B are siblings.
• A is father of D, so D is child of A.
• Therefore, E and D are children of two brothers (B and A).
• This makes E and D first cousins.
Answer:D. Cousin