The correct option is:
**A. Does not produce as much ATP and comes into action as an energy backup for aerobic organisms.**
Anaerobic respiration is less efficient than aerobic respiration in terms of ATP yield, typically producing just 2 ATP molecules per glucose molecule compared to aerobic respiration, which can produce up to 38 ATP. Anaerobic processes are often utilized by organisms when oxygen levels are low or during intense exercise, providing a backup energy source.
Options B, C, and D are incorrect:
- B implies that anaerobic respiration produces more ATP than aerobic respiration, which is not true.
- C incorrectly states that anaerobic respiration produces oxygen and glucose; it does not produce oxygen and glucose.
- D incorrectly states that anaerobic respiration requires oxygen; it does not.