What are the approximate unit prices of a 15-ounce can of crushed tomatoes that sells for $2.25 and a 32-ounce can of crushed tomatoes that sells for $3.99?
a) $0.16/oz and $0.21/oz
b) $0.10/oz and $0.30/oz
c) $0.20/oz and $0.09/oz
d) $0.15/oz and $0.12/oz