A science class is tracking the progress of plant growth. The class starts the experiment with a plant five centimeters high. The plant grows two centimeters each day. The model for plant growth "y" is given by: y = 2x + 5. What is the meaning of the y-intercept in this equation?
A: the y-intercept is the starting date
B: the y-intercept is two times larger than five
C: the y-intercept is the starting height of the plant
D: the y-intercept is the largest height the plant can grow