The straight line 2x + 3y k = 0, k> 0 cuts the X and Y-axes at A and B. The area of AOAB, where O is the origin, is 12 sq. units. The equation of the circle having AB as diameter is
A x²+y²+4x - 6y = 0
B x²+y²-6x+4y = 0
C X²+y²-42-6y=0
D x²+y²-6x+4y = 0