Mini 12 oz - $1.20 family 28 oz - $2.24 economy 40 oz - $3.60 dish detergent is sold in three different sizes. to save money you want to buy the size that gives you the best deal. determine which of the sizes has the best unit cost. a) all three sizes offer the same unit cost. b) the mini size of dish detergent is the best buy. c) the family size of dish detergent is the best buy. d) the economy size of dish detergent is the best buy.