I believe your answer is B, Because electrons are clinched to protons, most times, therefor there is not an electron microscope, but a ELECTRONIC Microscope will show the organism on a screen. hope that helped some<span />
<span>Invertebrate<span>, </span>any animal that lacks a vertebral column, or backbone, in contrast to the cartilaginous or bony vertebrates. More than 90 percent of all living animal species are invertebrates. Worldwide in distribution, they include animals as diverse as sea stars, sea urchins, earthworms, sponges, jellyfish, lobsters, crabs, insects, spiders, snails, clams, and squid. Invertebrates are especially important as agricultural pests, parasites, or agents for the transmission of parasitic infections to humans and other vertebrates. Invertebrates serve as food for humans and are key elements in food chains that support birds, fish, and many other vertebrate species.Apart from the absence of a vertebral column, invertebrates have little in common. Indeed, they are distributed between more than 35 phyla. In contrast, all vertebrates are contained within a single phylum, the Chordata. (Phylum Chordata also includes the sea squirts and some other invertebrate groups.) Invertebrates are generally soft-bodied animals that lack a rigid internal skeleton for the attachment of muscles but often possess a hard outer skeleton (as in most mollusks, crustaceans, and insects) that serves, as well, for body protection.</span>
The answer in the statement above is true, it is because it
is necessary to have large sample because diseases are unpredictable, which
will be difficult especially on isolated populations are being considered.
Having an isolated population could be hard to the researches because they only
have a limited people to observe, that is why they needed a large sample in
order to differentiate results and have enough sample to use.