The correct answer is A. A lost species will make different species not get their food, and it goes on like a big domino effect, eventually effecting hunans.
Because comets are darker colored so they need light to shine on them to be seen in the dark skies of space.
Some living thing's bodies are weaker than others. For the species to live, the strong ones of the species will not get sick, reproduce and create strong offspring. The weak will die out.
By using the equation F=ma (Force = Mass*acceleration), the answer is 15,100 N for the first one and 1.25 m/s^2 for the second.