My mother considered the idea of a child sleeping alone a cruel American practice, and therefore did not encourage it, even when we had the space.
It is a a trait that helps a creature survive in a particular environment.
The answer is C. This is because but is being used as a conjunction separating independent clauses in the other answers. You can remove but from A, B, and D, and you are left with 2 simple sentences.
I hope this helps!!!
It shows that the value of education can increase return on investment