Okay so I am very new to circles however I decided to give this one a shot for you. And I feel VERY strongly that it is not C. I believe it is A. I think this because with circles the equation is (x-h)^2+(y-k)^2=r^2 The h variable is the x coordinate at the center of your circle. The k variable is the y coordinate. In this question it is stating that the origin is the center which gives you (0,0). It also states the radius, r=5. Therefore when you put in all your known values into the equation you get, (x-0)^2+(y-0)^2=5^2 And just removing the unnecessary zeros and simplifying things you get, x^2+y^2=5^2
