Given a circle with a center at (1, 2) and a radius of 3, what would the
equation of the circle be?

A.(x - 1)^2 + (y-2)^2 = 3
B.(x + 1)^2 + (y + 2)^2 = 9
C.(x - 1)^2 + (y - 2)^2 = 9
D.(x - 1)^2 + (y - 2)^2 = 6