Which of the following objects could be used to construct a functional clock?

Question

a. A superball bouncing up and down many times on a hard floor.
b. A very low frequency tuning fork.
c. A ribbon fluttering back and forth in the wind.
d. A car that is bouncing up and down as it drives over a bumpy road.
e. A chair hanging by a bungee cord out a window.

Explain your responses.