Consider the following statements:

I. Closed systems rely exclusively on simple diffusion for transport, whereas open system rely on pumping mechanisms.

II. Transport within closed systems is more rapid than in open systems

III. Blood can easily be directed to specific areas in closed systems, but not in open systems.

IV. Closed systems operate better under higher pressure than do open systems.

The correct statements include

(A) I, II, III, IV

(B) I, II, III

(C) II, III, IV

(D) I, II, IV