The correct option is
B (4a,4a)Let us suppose square will be
ABCD,
vertex A will be lie on origin,
coordinates of A=(0,0)
coordinates of B=(at2,2at)
coordinates of C=(h,0). :- ( C will lie on x−axis. )
coordinates of D=(at2,−2at)
slope of AB =tan45∘=1. --(1)
we know that slope of AB=y2−y1x2−x1
put the value of x1,x2,y1,y2 from coordinates A & B,
so, slope of AB=2at−0at2−0
from equation 1, we know that,
2at−0at2−0=1
2at=at2
and t=2
if we consider the coordinated of B,
than B=(at2,2at)
put the value of ′t′
B=(4a,4a)
so, correct option will be 'B'