Find the intervals en which $f(x)$ is increaning, De intervals on which fix$)$ is decreasing, and the relative exerme points.

$1(x)=3x^4-84x^{3}17$

Find the intervals on which $f(x)$ is increasing. Select the correct choice below and, $f$ necessafy, fill in the antere box to complete your choioe.

A$.$ The function is increasing on $$

$($Type your anwer using interval notation. Upe a corma lo steparate answers as needed$)$

B$.$ There is no solution.

Find the intervals on which $f(x)$ is decreasing Select the correct choice below and, if necessary, the in the answer box to corrolete your choice.

A$.$ The function in decreasing on $$

$($Fype your answer using inlerval notation. Use a comma lo sebarate answers as needed $)$

B$.$ There is no solution.

Which statement regurding the relative extrema of the function is true? Chood the correct asswer below.

A$.$ The function has a relative minimum point at $x=24.$

B$.$ The function has a relative maximum point at $x=0$ and eretailue minimum point at $x=21$

C$.$ The function has a relative masmum point at $x=4.$

D$.$ The function does rot have an extreme point at $x=0.$