WAEC Biology 2020 Question 10

In an experiment, mould and yeast cells were transferred into an environment with low oxygen concentration. After a few days, the mould died while the yeast cells did not. Which of the following statements best explains the above observation?

1. A.The yeast cells carried out photosynthesis while the mould did not
2. B.Photosynthesis does not take place in the absence of oxygen
3. C.Respiration can take place in yeast cells in the absence of oxygen
4. D.Respiration does not occur in the mould