Economics question for college?

If Amazon.com raises its prices by 10 percent and, as a result, the quantity of books demanded on Barnesandnoble.com increases by 31 percent, what do comsumers consider the two Web sites to be?

A. Unrelated

B. Identical

C. Close substitutes

D. Close complements



By the way if you are taking Microeconomics with the "Microeconomics Second Edition by R. Glenn Hubbard and Anthony Patrick O'Brien, published by Pearson Prentice Hall" textbook in correlation with www.myeconweb.com I would like your help. Thanks in advance!Economics question for college?
This is elasticity (cross price elasticity) = % change in demand/% change in prices = 31/10= 3.1 this is highly elastic, implying substituability. Imagine Coke vs. Pepsi sell for one dollar. If coke raises its price to 100, I'm just going to buy the pepsi.



so the answer would be C



Good luckEconomics question for college?
c. one is a substitution for the other..





but we really need to know if amazon demand is reduced to make it more accurate