In 2015 and in 2016, consumers in Dexter purchased only books and pens. The prices and quantities for 2015 and 2016 are listed in the table. The reference base period for Dexter's CPI is 2015, and 2015 is also the year of the Consumer Expenditure Survey. The inflation rate in 2016 is percent. OA. 0.6 OB. 178.4 OC. 278.4 OD. 142.0 Item Books Pens Price $5 $2 2015 Quantity 7 8 2016 Price Quantity $10 4 $9 5