Why does aquaporin 1 (AQUA1) transport H2O orders of magnitude faster across the erythrocyte plasma membrane than GLUT1 transports glucose?

A.
GLUT1 has a higher Km for glucose than AQUA1 has for H2O.

B.
AQUA1 has a higher Km for H2O than GLUT1 has for glucose.

C.
AQUA1 does not undergo a conformational change when transporting H2O

D. AQUA1 undergoes a more rapid conformational change than does GLUT1.
E. AQUA1 & GLUT1 are both uniporters whose transport rates are identical.