Answer:
C
Explanation:
The first part of this is to represent the center.
It sits at (1,-1), so the left hand part of the equation is
(x - 1)^2 + (y + 1) = r^2
That means the answer has to be either B or C. D gets knocked out of the running because of the minus sign in the middle. D does not give a circle.
B is wrong because the y value should be plus. So the answer is C. Notice because the question is multiple choice you don't need to solve for r since all answers give r^2 = 36