Use the Following to Answer Questions

Multiple Choice

Use the following to answer questions :
The graph below shows the relationship between glucose concentration outside a cell and the rate of glucose diffusion across a cell membrane that has carrier proteins to facilitate diffusion.
-According to the graph, as the number of glucose molecules increases, the rate of diffusion

A) increases indefinitely.
B) decreases.
C) increases until a plateau is reached.
D) can either increase or decrease.
E) remains the same.