Answer:
The correct answer is "Short-term changes immediately affect individuals. Long-term changes gradually affect populations".
Step-by-step explanation:
Short-term is a compound word used to describe changes or effects that take place in a lapse of no longer than a year. On the other hand, long-term changes or effects take more than a year, and usually are of greater impact. In the case of the environment, short-term changes affect individuals immediately and take place in no longer than a year. Environmental long-term changes affect populations gradually, are evident after more than a year and usually are more drastic than short-term changes.