Hey,
I believe this answer is A: The desert plants are likely to be better at retaining water.
Which they do, and they have to cause water is very scarce in the desert unlike the rain forest.
Desert plants likely to be larger is not proven and most plants can vary in size.
Narrower stems may have something to do with it but that goes back to they have to hold more water so this is incorrect.
Brighter flowers doesn't have anything to do with water consumption within a plant so this is incorrect as well.
Hope this helps!
Brainliest is always appreciated if you feel its deserved.
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The continual input of energy, mostly from sunlight, sustains the process of life. Sunlight allows plants, algae and cyanobacteria to use photosynthesis to convert carbon dioxide and water into organic compounds like carbohydrates. This process is the fundamental source of organic material in the biosphere. There are a few exceptions to this, such as ecosystems living around hydrothermal vents on the ocean floor, which derive their energy from the chemical compounds such as methane and hydrogen sulfide. In either case, the overall productivity of an ecosystem is controlled by the total energy available.