Answer: C - introduction of an unchecked invasive species.
E- massive flooding.
Explanation:
The catastrophic event can be define as the event which can cause huge damage to the living and non-living factors of the ecosystem. It can make the environment unsuitable for the survival of the living beings and can become the cause of mass extinction.
C is the correct option because the introduction of invasive species can reduce the population of members of the native species if the invasive species compete with the native species for resources.
E is the correct option because the massive flood will wiped out the living beings and can destroy the landscape and property of the region where it occurs.
One way is to share your problems with a friend or parent and tell them how you are feeling. Get plenty of sleep as well and eat healthy, avoid any alcohol and drugs. Hope this helped.