A pendulum STARTS swinging from a maximum of 5 cm to minimum of -8 cm in 2.5 seconds. What is the equation that best represents this?

a) y = 5 cos [72(x)] -8
b) y = 13 cos [6.5(x)] -1.5
c) y = 5 cos [72(x-2.5)] -8
d) y = 6.5 cos [72(x)] -1.5

c) y = 5 cos [72(x-2.5)] -8