When Glycogen Synthase Is Phosphorylated, It

When glycogen synthase is phosphorylated, it

A) is inactive but can be allosterically stimulated by AMP.
B) is active in the synthesis of glycogen from UDP-glucose.
C) catalyzes synthesis of alpha-1,6 bonds between glucose molecules.
D) is inactive but can be allosterically stimulated by glucose 6-phosphate.
E) acquires a phosphate group on a tyrosine residue.