A local store sells boxes of pens. The cost of a box of pens and the number of pens in the box are related. You need 39 pens. Identify the independent variable in the relationship.
What is the independent variable?
A.
The cost of a box of pens
B.
The cost of each pen
C.
The number of boxes of pens you need
D.
The cost of the boxes of pens you need
E.
The number of pens in the box
F.
The number of pens you need