(C)Cori cycle
Explanation:
Generally, the glucose undergoes metabolism in the presence of oxygen to form ATP (Adenosine triphosphate) which is essential for the muscle contraction but during strenuous exercise, the body cannot meet the oxygen demand and the glucose undergoes metabolism in the absence of oxygen which results in the formation and accumulation of lactic acid. This accumulated lactic acid is moved to the liver and converted into glycogen thorough Cori cycle. Cori cycle takes place in the liver. Hence the reactions which change lactic acid into glycogen come under the Cori cycle. So, the correct answer is 'Cori cycle'.