Which equation represents a circle with center (h, k) and radius r in standard form?

Which equation represents a circle with center (h, k) and radius r in standard form?

• A. (x + h)^2 + (y + k)^2 = r^2
• B. (x - h)^2 + (y - k)^2 = r
• C. (x - h)^2 + (y - k)^2 = r^2
• D. (x^2 - h)^2 + (y^2 - k)^2 = r^2

Answer: (C)