Answer: A. plants produce oxygen during photosynthesis and they also need oxygen from the air for cellular respiration.
In the process of photosynthesis the plants in the presence of sunlight, water and carbon dioxide produces a carbohydrates as food and oxygen is liberated into the atmosphere. The process of photosynthesis takes place in day and plants avail oxygen from the roots and leaves for respiration. The food produced is broken down into carbon dioxide and water with the release of energy in the presence of oxygen during cellular respiration. Plants produce oxygen as a byproduct of photosynthesis and use oxygen for cellular respiration.
On the basis of the above information, A. plants produce oxygen during photosynthesis and they also need oxygen from the air for cellular respiration is the correct statement that describes the relationship between plants and oxygen.