I assume that the question here refers to the process of evolution. The "helpful variations" are small mutations that allow the organism to have a small advantage over other - and this organism can then pass this variation to its children better than other organisms, meaning that with time, more organisms will have it. This will accumulate over time and the percentage of organisms with this mutation will increase.
Answer:
I believe the correct answer here would be A. D comes close, but Starbuck's 'rule' is more of a request rather than an outright ban, as the open letter on their website states: "First, this is a request and not an outright ban. Why? Because we want to give responsible gun owners the chance to respect our request—and also because enforcing a ban would potentially require our partners to confront armed customers, and that is not a role I am comfortable asking Starbucks partners to take on."
It divides the earth into eastern and western hemisphere
That they migrated during the ice age over 12,000 years ago
