Answer
Option (a)
Work Step by Step
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).