Help me find the independent variable please In an experiment, 90 newborn flies are divided evenly into three separate
groups and placed in boxes inside an incubator that is maintained at a
constant temperature of 30°C. On a daily basis, the first group is given water
containing 1 mg/mL of sugar; the second is given water containing 2 mg/mL
of sugar; and the third is given water containing 3 mg/mL of sugar. After four
weeks, the average length of the flies in each group is determined.
Which factor is the independent variable in this experiment?
A. Number of flies in a group
B. Average length of flies in a group
C. Concentration of sugar in the water
D. Temperature of the incubator