An experiment is being conducted to determine if lack of sleep affects learning in ten year old children.

Parents are asked to keep a journal or log of the amount of sleep that their children get each night. Once reviewed, the groups of children that get at least 8 hours of sleep was compared to the group that got less than 6 hours of sleep.

In this comparison, what was the control treatment or group?

Group of answer choices

gender

children that got less than 6 hours of sleep

children that received at least 8 hours of sleep

age