D.Elements continuously cycle between the physical environment and living organisms.
Ecosystem is encompassing all the life on earth in the physical environment that supports it. An ecosystem involves both the biological (plants, animals, human beings) and non-biological (land, water, soil, and atmosphere) community which interacts as a system. More importantly, the living things are very dependent on the abiotic community since it cannot survive by itself. Every animal, plant and human needs the primary physiological needs of water, food and shelter provided by the abiotic system. <span> </span>
Among the listed plants above, the one that we can expect to grow lowest to the ground would be the hornworts. Hornworts are non-vascular plants which can be found both on water and land. Since these plants do not have a vascular system, it is hard for them to move water internally due to the force of gravity which explains why they cannot grow more above the ground.
It's A, a limiting factor is something that constrains the population size