4. Five students are discussing hexose structure. Student A says: D-glucose and b-glucosamine are different on C2.
Student B says: D-glucose and L-glucose are different on C5.
Student C says: D-glucose and D-glucuronic acid are different on C6.
Student D says: a-D-glucose and B-D-glucose are different on Cl.
Student E says: D-glucose and b-galactose are different on C4.
How many students are correct?
(A) 1
(B) 2
(C)3
(D) 4
(E) 5