When the continents separated, some of the same species ended up on different continents this was due from a. geologic time c. platetectonics b. evolution d. natural selection

Option C, platetectonics

Explanation:

According to the continental drift, the continents have separated from each other through the movement of tectonic plates on which they rest. The continuous movement and drifting of these tectonic plates towards or away from each other is called plate tectonics.  

As these tectonic plates gets drifted away from each other, the life forms on it also get drifted from the original land mass to a new continent.  

Thus, option C is correct

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.

when it is at an intermediate population density