Which of the following is the correct equation of a circle whose center has coordinates (1, 6) and radius = 4.
(x - 1)^2 + (y - 6)^2 = 16
(x - 1)^2 + (y - 6)^2 = 4
(y - 1)^2 + (x - 6)^2 = 16
(y-1)^2+ (x - 6)^2 = 4