Well, in general, world-wide I would say that the best answer is D. - political parties unite people who have the same views and would like to promote these views exercising political powers.
On a local scale, the parties need to follow laws (and in some countries, the law might only allow one party) and they might even only exist to support a certain candidate (but usually it's the other way: the candidate represents the party).
Assuming that this is referring to the same list of options that was posted before with this question, <span>the correct response would be the one having to due with the Middle ages "transitioning" into the Renaissance, since this is dealing with parts of history in discrete, compartmentalized periods of time.</span>