Answer:
I would say that the answer is A, or releasing ladybugs into a habitat.
Explanation:
This is the only "natural" way to control an aphid population. However, please note that as well as ladybugs, praying mantis's also eat aphids. But, the answer choice doesn't describe the option very well, so that is why I say that it is A.
<em>Hope it helps!</em>
A coral reef is a complex [ecosystem] of calcium carbonate shells that are home to microbes, algae, invertebrates, and fishes, and its high productivity helps provide great species richness.
Both plants and animals have these. It is a eukaryotic cell.