B. a process in which cells release energy in the absence of oxygen

Answer 1

The process you are describing is known as anaerobic respiration. In anaerobic respiration, cells produce energy without the use of oxygen, typically by converting glucose into energy-rich molecules like ATP while generating byproducts such as lactic acid (in animals) or ethanol and carbon dioxide (in yeast and some bacteria). This is in contrast to aerobic respiration, which requires oxygen to produce energy. Anaerobic respiration is often less efficient than aerobic respiration in terms of energy yield per molecule of glucose.