Final answer:
Plants create oxygen through photosynthesis, and this oxygen is used by humans and other aerobic organisms during cellular respiration. Humans do not produce oxygen through cellular respiration; instead, they consume it.
Step-by-step explanation:
The true statement among the given options is that plants create oxygen via photosynthesis, which is used by humans in cellular respiration. Photosynthesis is the process by which plants use sunlight, carbon dioxide, and water to produce glucose and oxygen. This oxygen is then crucial for aerobic organisms, including humans, because it is used in the process of cellular respiration, where glucose is converted into ATP, which cells use for energy. During cellular respiration, oxygen is combined with hydrogen to form water.
It is important to note that while all organisms perform cellular respiration using oxygen, it is not correct to say that humans or other organisms produce oxygen via this process. Additionally, oxygen is indeed naturally occurring in the atmosphere, but it is also continually synthesized by plants and some bacteria through photosynthesis. Lastly, while air does contain oxygen, it is primarily composed of nitrogen, not oxygen.