Assertion:
J.K. Rowlling's books are selling like hot cakes.
RI. People love the subject of the book written by Rowlling and the style of her writing.
RII. Rowlling uses very simple language so that every one understand that.
Answer: A
The interesting topic and the art of writing is a proper reason for the popularity of an author. Hence RI is a reason. RII is not the reason, because if the subject is not good, language does not help.