The correct option is C In the absence of O2
Respiration is the catabolic process, which releases energy stored in reduced substrates and also results in the synthesis of important biochemical intermediates. Respiration can be aerobic when it occurs in presence of oxygen or anaerobic when it occurs in absence of oxygen. Aerobic respiration releases considerably more energy and results in complete oxidation of reduced substrates. Anaerobic respiration is an incomplete oxidation process. during germination seed respire in the absence of oxygen.