The correct answer is the following.
It seems that there is no question here, just a series of statements.
Although there is no question included, we could assume that we have to choose the sentence best written. If that is the case, then the correct option is A) Though most people take it for granted now, the nationwide admission of students to colleges and universities based on academic merit.
Among the other options, option A is very specific, concrete, and understandable. It does not need anything else. The clearest, specific, and direct the sentence, the better to a correct understanding.