C: Lactic acid fermentation
Cellular respiration without oxygen is called anaerobic respiration. ETS (or electron transport chain) reactions happen as the last step of aerobic cellular respiration, therefore it is incorrect.
Lactic acid fermentation is a metabolic process by which glucose and other six-carbon sugars are converted into cellular energy and the metabolite lactate, which is lactic acid in solution. It is an anaerobic fermentation reaction.