<prompt> Increased formation of ketone bodies during fasting is a result of which of the following?Increased oxidation of fatty acids as a source of fuelDecreased formation of acetyl CoA in the liverDecreased levels of glucagonIncreased glycogenesis in muscle  <response>: During a fast, catabolism is increased to provide additional sources of energy. This is characterized by increased utilization of fatty acids. When the production of acetyl CoA produced by enhanced β-oxidation exceeds the oxidative capacity of the citric acid cycle, ketone bodies are formed. During fasting conditions, glucagon concentrations are increased and glycogenesis is inhibited due to limited energy availability. Acetyl CoA production in the liver is increased due to enhanced β-oxidation. 