Find the equation of the circle with center (0, 0) and radius 5.
Correct: A
The general equation of a circle with center (h, k) and radius r is (x - h)^2 + (y - k)^2 = r^2. Given the center (0, 0) and radius 5, we substitute h = 0, k = 0, and r = 5 into the equation to get (x - 0)^2 + (y - 0)^2 = 5^2, simplifying to x^2 + y^2 = 25.