Which of the following statements about Krebs cycle is/are true? (I) Acetyl CoA initiates the Krebs cycle. (II) The two-carbon compound (acetyl-CoA) combines with a four-carbon (oxaloacetate) to form the six-carbon compound citric acid. (III) A two-carbon group is added to the Krebs cycle during each complete cycle, and it also involves oxidation of two carbon atoms into carbon dioxide.
