A: That answer is illogical at best
B: It makes sense, the smaller you are, the less food you need
C: This would need extensive studying of key deer ancestry to figure out
D: This could work over thousands of years. But an overpopulation of one wouldn't push out the other. Ungulates (hooved mammals) of different species often work together.
B, sounds like your best choice.
Mass and distance affect the gravitational force.
Answer:
it means the object you are talking about uses photosynthesis
Planting plants would increase how much carbon dioxide they can take in as a whole, reducing the amount of carbon dioxide that goes into the atmosphere and therefore counteracting/minimalising our affecting the carbon cycle.