At which stage is a child able to read and process information that reflects multiple points of view? what grade(s) is the child likely to be attending? stage 1 - first and second grades stage 2 - second and third grades stage 3 - fourth to eighth grades stage 4 - eighth grade and beyond

I believe the answer is:  Stage 4; eighth grade and beyond
In the stage 4 of reading stages, the Children tend to already developed the ability to understand the content of information from various perspectives.
For example, when reading a historical battle, children in previous stages would probably only see it as a battle of right versus wrong, while those in stage 4 would understand the reason why each sides have their own reason to be involved in the fight.