What is the equation of a circle with the center at (2,5) and a point on the circle at (-2,6)?
a. (x-2)² + (y-5)² = 36
b. (x-2)² + (y-5)² = 25
c. (x+2)² + (y-6)² = 36
d. (x-2)² + (y+5)² = 36