c. $0.79
The unit price is cost of each individual unit or in this example a can of peas. We know that 18 cans of peas cost $14.22, so we divide the whole cost by the number of units so $14.22 divided by 18. This shows us that each can cost $0.79, or answer "c". Knowing how many ounces of peas in each can is not necessary to the equation.
