The midpoint (x, y) and the end point (x2, y2) are known. Find (x1, Y1) using the midpoint formula.

a. (x1,y1) = (2x + x2, 2y+y2)

b. (x1,y1) = (2x - x2, 2y - y2)

c. (x1,y1) = (x + x2, y + y2)

d. (x1,y1) = (x - x2, y - y2)