Refer to the Figure Above and Then Answer the Question

Refer to the figure above and then answer the question that follows.
-For this type of transport to take place, which of the following must be true about the interior and exterior environments?

A) The amount of glucose outside the cell must be less than the interior concentration.
B) The glucose concentration must be higher outside the cell than inside the cell.
C) The glucose concentrations on both sides of the cell are the same.
D) A transport protein is involved, so it doesn't matter what the concentrations of glucose on either side of the membrane.