Answer:
C
Explanation:
It's pretty simple really, just find the <em>Benefit</em>. Pollution is definitely a harmful effect, disease is also not a benefit, and depletion of fish population is bad, so easing demand on commercial fisheries is the answer
It carries signals for the body through nerves (answer 3)
<span>Mutations generated in a species gene pool important because mutations cause evolution.</span>
These preparations are called Vaccines. A vaccine is a biological preparation that provides active acquired immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing micro-organism and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins.