Answer the following question: Fact 1: Harming an animal species causes that animal 's population to decrease. Fact 2: If mortality is greater, then the population decreases. Given the two facts above, what can cause a population decline?

Possible answers:
1). wind;
2). magma;
3). bacteria;
4). influenza;
5). mortality;
6). a pathogens;
7). reproduction;
8). parasites;
Answer:
5).