PLS HELP ILL GIV BRAINLIEST 20 POINTS

its A Or C

Explanation:

The 2 correct answers are C and D (the last 2)

Explanation:

Let's do process of elimination:

Invasive Species are species that invade habitats or areas they don't belong in, so it is obviously not A. They definitely affect existing populations, usually in a negative way, so it is not B. They sometimes don't have predators, which can cause more damage to the ecosystem, so one answer is C. Finally, one of the big reasons why invasive species are bad new is because they can reduce, or even end native populations and harm the ecosystem, so D is another answer. I hope this helped!