9. During exercise, which of the following is not likely to happen in muscle cells?
(A) LDH (lactate dehydrogenase) is increased and lactate fermentation takes place
(B) IDH (Isocitrate dehydrogenase) is activated by ADP and TCA cycle increases
(C) PDH (Pyruvate dehydrogenase) phosphatase is activated by Ca't and TCA cycle increases
(D) PDH (Pyruvate dehydrogenase) kinase is activated by ATP and TCA cycle increases