Given $g(x)=16x^4-125x,$ find the critical numbers.

Select the correct answer below:

$\frac{-20\sqrt[\phantom{2}]{-1200}}{32},\frac{-20-\sqrt[\phantom{2}]{-1200}}{32}$

$-\frac{5}{4}$

$\frac{5}{4}$

$\frac{5}{4},\frac{-20\sqrt[\phantom{2}]{-1800}}{32},\frac{-20-\sqrt[\phantom{2}]{-1200}}{32}$