A is the son of B; but B is not his mother. C is the son of D. A and C are siblings. E is the only daughter of B. How is E related to C?

Sister

Note:

↑ or ↓ ⇒ Upward or downward line shown "generation gap" .

   =    ⇒ Double lines shown "relation b/w Husband & Wife"

   —   ⇒ single line shown "relation between them other than Husband & Wife".

   +   ⇒ Plus sign shown " Male".

   -   ⇒ minus sign shown " Female".

E is the sister of C.