Which of the following is a result of shifting a circle with equation (x - 2)2 + (y - 3)2 = 25 up 2 units?   a. both the x- and y-coordinates of the center of the circle decrease by 2.   b. the x-coordinate of the center of the circle increases by 2.   c. both the x- and y-coordinates of the center of the circle increase by 2.   d. the y-coordinate of the center of the circle increases by 2.