1. What animals live in Canada?

2. Which animals live in Canada?
3. What animal lives in Canada?
4. Which animal lives in Canada?
- Many animals live in Canada.
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Which questions are suitable for the answer?

I would use "what" unless I had been given a specific list of animals beforehand.

The answer, though, doesn't really go with any of those questions. The questions are asking for specifics. The answer is far too general.

What/Which animals live in Canada?
Elk, deer, beaver, and wolves live in Canada.

All of the questions are suitable for the answer, as they are all asking about the animals that live in Canada. The statement "Many animals live in Canada" can be used to answer all four questions.