Kate gathered three boxes of the same size made of different materials: glass, clear plastic, and aluminum painted black. she placed them on a window sill i0n the sun for an hour and then measured the warmth of the air in each box. in this experiment, the types of box materials are a(n)

a. independent variable.

b. constant

c. control

d. dependent variable

A. Independent Variable.

Explanation:

The independent variable can be changed, altered and manipulated in an experiment. This is done to observe such a change over the dependent variable.

The three boxes of different materials is an example of independent variable. The effect of which can be observed on the warm air present in each box which is the example of dependent variable.