If Necessary, Our Muscles Can Rely Upon an Anaerobic (Fermentative)

If necessary, our muscles can rely upon an anaerobic (fermentative) pathway to metabolize glucose, but this can only last a short period of time. Why can't our cells survive very long under such anaerobic conditions?

A) Fermentation doesn't extract enough ATP from glucose to sustain our energy-craving cells.
B) Anaerobic conditions create a "carbon dioxide debt" that must be repaid before cells die.
C) The ethyl alcohol that builds up in muscles as a result of fermentation is a toxin.
D) Lactic acid causes the cell to die when it's exposed to even lower concentrations.