The enzyme phosphorylase kinase catalyzes a modification of glycogen phosphorylase that controls its activity. How does phosphorylase kinase modify glycogen phosphorylase?

a. adenylation, which transfers an adenosine from ATP to the phosphorylase enzyme direct AMP

b. binding to glycogen phosphorylase after hydrolysis phosphorylation, which transfers a phosphate from ATP to the phosphorylase enzyme

c. a conformational change driven by the energy released when ATP is hydrolyzed