All of the following statement about cell membrane fluidity are correct EXCEPT for one which is______________.  
A. membrane fluidity allows for interactions to take place within the membrane 
B. membrane fluidity makes it possible for clusters of membrane proteins to assemble at 
particular sites 
C. because of membrane fluidity, molecules that interact can come together, carry out the 
necessary reaction, and move apart 
D. the fluidity of the cell membrane helps maintains its role as a rigid barrier between the inside 
and outside of the cell environment