In the Synthesis of Cytidine (Bz Protected),the Amino Group at Position

In the synthesis of cytidine (Bz protected) ,the amino group at position 4 (N⁴) of cytosine is protected with a benzoyl protecting group because

A) the primary amino group would react faster than the secondary N¹.
B) The cytosine reagent would not be soluble in the reaction medium.
C) Cytosine needs to be activated with the benzoyl protecting group.
D) The amino group needs to remain protected after hydrolysis of benzoyl groups.
E) The activation of the primary is needed for the reaction with the d-ribose.