pyq/2018/csat/38

A bookseller sold 'a' number of Geography textbooks at the rate of Rs. x per book, 'a + 2' number of History textbooks at the rate of Rs. (x + 2) per book and 'a - 2' number of Mathematics textbooks at the rate of Rs. (x - 2) per book. What is his total sale in Rs. ?

(A) 3x + 3a

(B) 3ax + 8

(C) 9ax

(D) x^3 a^3