I came across this sentence today but am not sure if this is a reduced relative clause.
These six categories are also consistent with those used to group the multiple-choice questions included in this chapter.
Can that/which are be understood to be in the sentence?
These six categories are also consistent with those that/which are used to group the multiple-choice questions included in this chapter.
If the above sentence is correct,and since that/which represents those
can the relative clause be viewed as:
Those are used to group the multiple-choice questions included in this chapter.