Introduction to Biochemistry - Quiz 3.8.3

Low blood glucose stimulates the release of Glucagon.
Both liver and muscle cell respond to Insulin. (Muscle cell do not hydrolyze glycogen other than local needs)
Glucose absorption from the blood is simulated by Insulin. (High blood glucose means cell should absorb glucose)
Glycogen synthesis is stimulated by Insulin. (High blood glucose means they should be stored)

Glucagon means low blood glucose, therefore we should not synthesize glycogen, therefore:

The kinase activity of PKA indirectly activate glycogen phosphorylase.
The kinase activity of PKA directly inactivate glycogen synthase.

Here is the indirect part - (Protein Kinase A) phosphorylate and activate (Phosphorylase Kinase), (Phosphorylase Kinase) phosphorylate and activate (Glycogen Phosphorylase).

I know, that's a mouthful.

A liver cell is building glycogen because there is high blood glucose. Therefore we have insulin signalling.

It couldn't be glucagon signalling, glycogen phosphorylase activity or PKA activity.

So, well, the answer can only be GSK inactivation.