The double number line below shows the prices for a certain number of packs of spaghetti at a store. Which statement correctly gives and explains the price of 9 spaghetti packs?
A. $18, because the price of each pack is $2
B. $72, because the price of each pack is $8
C. $80, because the price of each pack is $8
D. $144, because the price of each pack is $16
