Some large fish allow smaller fish to swim inside of their mouths without eating the smaller ones. The smaller fish get to feed inside the larger fish's mouth, the larger fish gets parasites removed from its teeth. This is an example of:

Mutualism. Both animals are benefiting from eachother.

Explanation:

a. as the temperature increases, the kinetic energy of the gas molecules increases & the molecules move faster & further away from each other.

b. if you decrease the temperature of a fixed amount of gas at constant pressure, the combined gas law reduces to charles's law. in this case, volume will also decrease.

i think it's c