Jillian then applies 1 mL of four different types of antibiotic to the different plates. The plates are incubated in the dark at the same temperature and humidity for one week. Jillian records the number of colonies that remain on each plate at the end of each day during the week. Her results appear below. Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7
Plate 1 100 90 80 70 60 50 40
Plate 2 100 87 69 55 43 43 43
Plate 3 100 95 110 125 150 138 104
Plate 4 100 50 37 16 0 0 0

What is the outcome variable (dependent variable) in Jillian's experiment?
A.
the type of antibiotic that is used
B.
the type of bacteria that is being tested
C.
the number of bacterial colonies that remain
D.
the initial number of bacterial colonies