geometry
posted by kieara on .
Question: 2 of 40: Which of the following circle equations represents a circle whose center is at (0, 0)?Select one of the options below as your answer: A. x2 + y2 = 45 B. (x − 3)2 + (y − 5)2 = 0 C. (x + 3)2 + (y − 3)2 = 0 D. x2 + (y − 1)2 = 1

No it isn't.For example:
when (x2)^2+(y3)^2=16 equation,whose center is (2,3) and radius is 4.
there is an only a is true.Because whose center coordinate is (0,0). 
The equation x2 + y2 − 2x + 2y − 1 = 0 is the general form of the equation of a circle. What is the standard form of the equation?