If one of the lines of pair of straight lines $ax^2 + 2hxy + by^2 =0$ bisects the angle between the co-ordinates axes, then :

Question

( A ) $(a+b)^2 = h^2$
( B ) $(a+b)^2 = 4h^2$
( C ) $a^2 + b^2 = h^2$
( D ) $a^2 + b^2 = 4h^2$