They will give all the help to new staff.

The new staff will be given all the help by them

The new staff will have been given all the help by them

The new staff will be given all the help by him

The new staff will be given all the help by us

Explanation

Option A is the correct answer because have been was mentioned in second option which is used for perfect tense, the word him was mentioned in third option which is used for he not they, the word us was mentioned in fourth option which is used for we not they.