Given below are two statements:
Statement (I): There is accumulation of lactic acid in skeletal muscles during vigorous exercise.
Statement (II): Lactic acid is reconverted into pyruvic acid during resting stage of skeletal muscles.
In light of the above statements, choose the most appropriate answer from the options given below.

During vigorous exercise, the oxygen demand of skeletal muscles exceeds the oxygen supply. To meet the energy requirements, skeletal muscles undergo anaerobic respiration, where pyruvic acid is reduced to lactic acid by the enzyme lactate dehydrogenase. This leads to the accumulation of lactic acid, causing muscle fatigue. Thus, Statement (I) is correct.

During the resting stage, when adequate oxygen becomes available, the accumulated lactic acid is oxidized back into pyruvic acid. A portion of this pyruvic acid is oxidized in the muscles to generate ATP, while the rest is transported to the liver to be converted into glucose (Cori cycle). Thus, Statement (II) is also correct.

Both Statement (I) and Statement (II) are correct.

Answer: Both Statement (I) and Statement (II) are correct.