Explain why a species that eats only two species of plants may have a higher probability of becoming endangered than a species that eats ten species of plants?

If species A survive only by eating 2 species of plants, then if any of those plants' population decrease, then Species A would have a severe decrease in food. But if Species B survive on 10 plants, even if all of the numbers of those plants decrease, they still have a wider range to find food. So this is why Species B has the better chance of surviving.