Which of the Following Can Prolog Conclude from the Following

Multiple Choice

Which of the following can Prolog conclude from the following program? parent(jill,sue) .
Parent(jill,sally) .
Parent(john,sue) .
Parent(john,sally) .
Sibling(X,Y) :- parent(Z,X) ,parent(Z,Y) .

A) parent(jill, john)
B) sister(sue, sally)
C) sibling(sue, sally)
D) sibling(jill, sue)