Question

Which of the following must be true for diffusion to occur?
A.Molecules or particles must have different sizes.
B.Special Protein Channels must always be avalable.
C. There must be areas of different concentrations.
D Energy must be avilable.

Answer 1

C. There must be areas of different concentrations.

Answer 2

@thewinterfawn is absolutely correct ;-) C. There must be areas of different concentrations.