The straight line 2x+3y-k=0 (k>0) cuts the x-and y-axis at A and B. The area of AOAB is 12sq. units, where O denotes the origin. The equation of circle having AB as diameter is?
a) x²+y²-6x-4y=0
b) x²+y²-6x-4y=13
c) x²+y²+6x-4y=0
d) x²+y²-6x+4y=0
e) x²+y²+6x+4y=13