Plants create oxygen through the process known as:

Plants create oxygen through photosynthesis, which is the process by which they convert light energy, typically from the sun, into chemical energy in the form of glucose. During photosynthesis, plants take in carbon dioxide from the atmosphere and water from the soil. Using light energy, they transform these inputs into glucose and release oxygen as a byproduct.

This process is vital not only for the plant's own growth and energy needs but also for the Earth's atmosphere because it produces the oxygen necessary for most living organisms to survive. Photosynthesis occurs primarily in the chloroplasts of plant cells, where chlorophyll captures sunlight.

The other processes mentioned—respiration, transpiration, and metabolism—do not directly relate to the production of oxygen. Respiration involves the consumption of oxygen to release energy from glucose; transpiration is the movement of water through a plant and its evaporation from aerial parts, mainly leaves; and metabolism encompasses all the biochemical reactions in an organism, including those for growth, energy production, and other vital functions, but it is not specifically linked to the production of oxygen.