Bite wounds are often serious as they may lead to an infection in which two or more

Bite wounds are often serious as they may lead to an infection in which two or more species of pathogens act together to produce an effect greater than the sum of effects if each pathogen were acting alone. This is referred to as a bacterial infections.

Mountains.

Explanation:

This is because the land is going up, creating a "hill" above the ground.

When the land slides by each other, it could create earthquakes. But since this isn't an option, the only other choice that makes sense is mountains.