Last Year You Purchased 20 CDs at $12 a Piece

Last year you purchased 20 CDs at $12 a piece, 10 shirts at $15 each, and 5 sweaters at $30 each (total spending equals $540) . This year you buy 18 CDs at $15 each, 10 shirts at $16 each, and 6 sweaters at $36 each (total spending equals $640) . If last year's index was 100, this year's index

A) is 119.6.
B) is 118.5.
C) is 83.6.
D) is 30.