The correct answer is: [D]:
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→ " redwood tree forests " .
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<u>Note</u>: Let us consider the other answer choices.
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Choice: [A]: "garden flowering plants" ; is incorrect — since these are not generally considered to be part of a true or traditional "ecosystem" ; and especially since "garden flowering plants" are, in fact, "flowering plants" — which means that they are "angiosperms" — <em><u>Not</u></em> "<em><u>gymnosperms</u></em><em> </em>".
→ Rule out: " Choice: [A] " .
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Choice: [B]: " ferns and liverworts " ; is incorrect — since <em><u>both</u></em> ferns — as well as liverworts —<u><em> are Not </em></u><u>"</u><u><em>gymnosperms </em></u>".
Liverworts are "bryophytes" {which lack true vascular tissue] ; and ferns are "pterophytes" ["seedless vascular plants"].
→ Rule out: " Choice: [B] " .
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Choice: [C]: " mosses and horsetails "; is incorrect ; since <em><u>both</u></em> mosses — as well as horsetails — <u><em>are Not </em></u><u>"</u><u><em>gymnosperms </em></u>". Mosses are "bryophytes" (see aforementioned) ; and horsetails are "non-seed bearing plants" that spread vegetatively [underground; by asexual reproduction — <em><u>and Not by seed</u></em><em> .</em>].
→ Rule out: " Choice: [C] " .
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Choice: [D]: " redwood tree forests " ;
— is the only answer choice provided that is a "gymnosperm".
Furthermore, the "redwood tree" is a conifer (i.e. "coniferous; or, "cone-bearing" plant} that reproduces through seeds spread by "cone") — and all "conifers" are a type of "gymnosperm."
Furthermore, "redwood trees" grow large and tall, and redwood forest communities within an ecosystem; due to there size and presence, are: "<em><u>known to be important in maintaining the balance of carbon in an ecosystem</u></em>."
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→ As such, the correct answer is:
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→ Answer choice: [D]: " redwood tree forests " .
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Hope this helps!
Best wishes to you in your academic endeavors
— and within the "Brainly" community!
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