A circle is centered at (3, 8) and is tangent to the x-axis. Write its equation in standard form. A) (x - 3)2 + (y - 8)2 = 9 B) (x + 3)2 + (y + 8)2 = 9 C) (x - 3)2 + (y - 8)2 = 64 D) (x + 3)2 + (y + 8)2 = 64