Answer:
E) Certain environments can lead to an increased risk of developing certain diseases.
Explanation:
The lesson states that specific environments can increase the chance of health problems.
A control variable is a scientific experiment in which the experimental element is unchanged throughout the experiment
a control group is a group in an experiment that does not receive the treatment by the researchers (untouched by them) and used to see the changes between the controlled group and that of the group that received the vial
hope this helps
