Mr. Wittmer notices that his classroom is covered in a strange green slime. Avi tells him that coconut juice will get rid of the slime. Mr. Wittmer decides to check this out by spraying half of the classroom with water and coconut juice. He sprays the other half with water. After 3 days of treatment, there is no change in the appearance of the green slime on either half of the room. Identify the:

control group

independent variable

dependent variable