What is the solution set to $8\left(2^{x-3}\right) \leq 20-4^x$?
A$(-\infty, \infty)$
B$(-\infty, 2]$
C$(0,20)$
D$[2, \infty)$
A$(-\infty, \infty)$
B$(-\infty, 2]$
C$(0,20)$
D$[2, \infty)$