Carla and Jonah are working together to determine if quadrilateral CDEF with coordinates C(2, 3), D(1, 2), E(4, 1), and F(5, 3) has perpendicular sides.

Carla sets up the following equations:
m^cd = 2-3/1-2
m^de = 1-2/4-1

Jonah sets up the following equations:
m^cd = 2-3/1-2
m^ef = 3-1/5-4

Who is on track to get the correct answer, and why?
A. Carla is on the right track because she is finding the slopes of consecutive sides to check for perpendicular sides.
B. Carla is on the right track because she is finding the slopes of the opposite sides to check for perpendicular sides.
C. Jonah is on the right track because he is finding the slopes of the opposite sides to check for perpendicular sides.
D. Jonah is on the right track because he is finding the slopes of consecutive sides to check for perpendicular sides.