The polynomial which is factored completely is  as these are not further factored.    Â
Step-by-step explanation:
To find : Which polynomial is factored completely?
Solution :
We factor the given polynomial one by one,
1)
2)
3)
4)
This expression is can not be factored with rational number as
Discriminant D<0 so there is no rational roots.
So, The polynomial which is factored completely is  as these are not further factored.