Question

select the text from the paragraph that best helps you understand that viable means usable. there may be more than one correct choice. parasitic relationships are often the most familiar types of symbiotic relationships. a common example is a flea living on a dog. in cases like these, the parasite gains a viable habitat to support its life cycle, while the host is harmed.

Explanation:

To understand that "viable" means "usable", we look at the context. The sentence says the parasite gains a viable habitat to support its life cycle. A habitat that supports the life cycle must be usable (functional) for the parasite. The phrase "to support its life cycle" clarifies that the habitat is usable as it fulfills the parasite's needs. So the relevant text is "to support its life cycle" (along with the mention of the habitat, but the key part showing usability is the purpose of the habitat).

Answer:

to support its life cycle