activation of pyruvate carboxylase by acetyl-CoA

a. This is a signal that pyruvate can be shunted into gluconeogenesis instead of being oxidized in the citric acid cycle. In addition, it is a signal of unbalanced fat and carbohydrate metabolism
b. This is a signal that part of available pyruvate can be metabolized into oxaloacetate, when the energy charge is low and production of additional ATP through the citric acid cycle is required.
c. This is a signal that pyruvate can be oxidized in the citric acid cycle instead of shunted into gluconeogenesis. In addition, it is a signal of activation carbohydrate metabolism
d. This is a signal that pyruvate can be oxidized in the citric acid cycle as well as can be shunted into gluconeogenesis. In addition, it is a signal of activation fat metabolism