Which structure represents a phosphorylated subunit of glycogen as described in the passage?

The structure that represents a phosphorylated subunit of glycogen as described in the passage is D.

The increased calcium availability binds to the calmodulin subunit and activates glycogen phosphorylase kinase. AMP activates glycogen phosphorylase b by changing its conformation from a tense to a relaxed form. This relaxed form has similar enzymatic properties as the phosphorylated enzyme.