The correct answer is - physically dettering herbivory, protection from frost, and minimizing evaporation.
The plants have developed multiple traits that help them in multiple different circumstances, and some of those traits are the thorns and the hairs on their steams and leaves.
The thorns primarily serve for protection of the plant. They are very sharp and give a painful sting (occasionally poisonous one), so they are a physical protection from the herbivores that would try to eat parts of the plants.
The hairs have multiple functions. They are like a coat that helps the plant to not be affected by frost, help to stop the evaporation, and also partially manage to stop most of the insects that feed on plants.
Explanation:
The division comprises a tremendous diversity of plants among its four subgroups: psilopsids, leafless and rootless primitive forms commonly known as whisk ferns (though not true ferns); sphenopsids, feathery leaved plants commonly called horsetails; lycopsids, low-lying plants called club mosses; and pteropsids,
So what would happen if photosynthesis suddenly stopped happening? If photosynthesis came to an abrupt end, most plants would die within short order. ... That's because for photosynthesis to cease to exist, Earth would have to plunge into darkness.
They should be limited to suit your needs not overdoing it or underdoing just to a healthy weight.
