Ans.C. Lactic acid
Anaerobic glycolysis results in the accumulation of cellular lactic acid in almost every organ having reduced perfusion.
Lactate accumulation also causes reduced pH.
Carbon dioxide and creatinine would increase in the involvement of the lung and the kidneys respectively. But these are not common for every organ involvement.
Troponin I is increased in irreversible injury to the myocardium and is the best marker for diagnosing MI.