College Algebra (10th Edition)

RECALL: (1) The general form of a circle's equation is: $x^2+y^2+ax+by+c=0$ (2) The standard form of a circle's equation is: $(x-h)^2 +(y-k)^2=r^2$ (3) The general form can be transformed to standard form by completing the square (as can be seen in Example 4 on page 185 of the textbook). Thus, the answer is Option (a).