You decide to purchase an annual membership that cost $25. Your opportunity cost of purchasing the membership is

a. the price you pay for the membership and the value of time spent for purchasing

b. the price you pay for the membership, but not the value of time spent for purchasing

c. the value of time spent for purchasing, but not the price you pay for the membership

d. neither the price you pay nor the value of time spent for purchasing

The book industry's net dollar sales grew at annual rate of 3.2% in2006 and 3.9% in 2007. The consumer price index(CPI) for 2005 was 195.3. In 2006, the CPI is 201.8 and the CPI was 207.34 for 2007. Based on the information, we can say the book industry's net dollar sales

a. grew at a faster rate than inflation in 2006 and 2007

b. grew at a faster rate than inflation in 2006 , but not in 2007

c. grew at the same as inflation in 2006 and 2007

d. grew a slower than inflation in 2006 and 2007