Sentence Correction (SC) | Re: QOTD: Schistosomiasis, a disease caused by a parasitic worm

I don’t have a whole lot to say about (A). The first thing I notice is the modifier “that are the parasite’s hosts” – and that seems like a reasonable way to modify “the freshwater snails.”

The pronoun “its” also jumps out at me, and that would have to refer to “the parasite’s”, since that’s our nearest (and most logical) singular. And that’s fine, too: “…the freshwater snails that
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