A certain school implemented a reading program for its students, with the goal of getting each student to read 6 books per month year-round. If the school has c classes made up of s students in each class, how many books will the entire student body read in one year?	Choose the correct option.
A) 20 cs  B) cs / 2  C) 72 cs  D) ( 2 cs ) / 12  E) ( 24 c ) / s

Rationale: "ans : c solution : simple multiplication s students , c classes , 6 books / month = 72 books a year total number of books = 72 cs"
Answer: C