we are given
"if it is a square,then it is a quadrilateral "
Contrapositive statement:
Suppose, we want to make contrapositive of
if p then q
it's contrapositive will be
if not p then not q
so, we can make contrapositive of our given statement
we get
"if it is not a square,then it is not a quadrilateral "
so, figure-B.........Answer