Which of the following is not true about nonnative species? a. They can have positive impacts on an ecosystem. b. They can have negative impacts on an ecosystem. c. They can be introduced within their natural range. d. A nonnative species can be an invasive species. Please select the best answer from the choices provided A B C D

C). They can be introduced within their natural range.

Explanation:

Non-native species are described as the species that are introduced or occurred outside their natural range which could be a different region or country. It primarily involves 'exotic' species.

As per the question, the third statement i.e. 'they can be introduced within their natural range' is false regarding non-native species as the very name implies that they are introduced outside or apart from their natural range. The other statements are true as non-native species may have positive as well as negative effects(which includes invasion also) on the ecosystem. They offer certain economic advantages and also help in rescuing or protecting the native species while at the same time pose a threat to them due to having certain selective advantages like quicker growth, more impactful dispersal etc. Thus, option C is the correct answer.

16.) true

17.) true

18.) it doesn't say

19.) true

20.) false

explanation: