The answer to this is B rhythm. People are familiar with rhythm as something that is done in a repeated manner. For example, some people have the tendency to follow the rhythm that is taught to them so that they can be uniform with the rest of the dancers. In art, rhythm is still being done, especially in paintings. Have you ever wondered why certain elements seem to be repeated in paintings?
This is not only to make the painting look more cohesive. Instead, this is being done to ensure that the whole painting will manage to tell its story accurately. This is also the same with songs. Some portions are repeated to let the listener know that he/she is listening to the same song.
B is the answer to this question. Have you ever looked at an outwork and you have realized that it seems so cohesive? It may be because of the rhythm that you can find in the picture. If the elements will not be repeated, there may be some aspects that will seem out of place and this is not the effect that the artist may want.
The uniformity of the various elements will also make the whole picture come together. If the elements will be all over the place, those who are looking at the picture may only end up getting confused with the whole picture or the artwork that they are viewing.