Let $f(n)=6n^4-23n^3+22n-271.$ Then the following is $($are$)$

true:

Select ALL correct answer$($s$).$

$f(n)is(n^4).$

$f(n)isO(n^4)$

$f(n)is(n^4)$

$n^{2}f(n)is(n^6).$

$[f(n){]}^{2}is(n^6)$