A vitamin degrades in the body according to the function represented in the table, where $x$ is the time in hours and $f(x)$ is the dosage in milligrams.

$x$	$f ( x )$
0	500.00
4	158.20
8	50.06
12	15.8
24	0.50

What was the original dose?

A0.50 milligrams

B8 milligrams

C24 milligrams

D500 milligrams