It is already simplified unless the variables have a value
It brought prosperity to many parts of the Central America , helped protect rain forest's , and improved trading with other countries
The best answer to this question is:
C. A forest fire that was caused by lightning.
A forest fire could kill for example all the individuals of a certain species in a given area - this would be independent of the population density of the species. All the other factors would affect the population the more, the more dense it is.
,
Dark Matter only: detected through its gravitational attraction, has mass, most common form of mass in the halo of the Milky Way Galaxy, likely to consist of subatomic particles
Dark Energy only: inferred to exist from the measured acceleration of the universe's expansion, the proposed source of a universal repulsive force
BOTH: the universe contains more of this than it contains matter made from atoms, we do not know what it is made of
NEITHER: blocks light from stars behind it, "dark" because it emits only infrared light