Hello there!
Your answers: Plot usually centers on character and Incidents that arise naturally from the character present an effective plot.
I would not agree that there would not be a relation between both the plot and the character. I disagree on this area.
Example: If you were to ever to the book 'the hunger games' as an example, there was a plot. The plot within the first book was that Katnis Everdeen's sister was chosen to be apart of the Hunger Games, but, she didn't want for this to happen. So she took her place. And within the whole book, it explain her attitude and so on within the plot.
Therefore, this would be one of an example of why I would choose both the bottom two answer.