To find the unit rate price per ounce of the root beer, you can divide the total cost by the total volume in ounces.
The total cost is $3.20 for a 64 oz. bottle.
To calculate the unit rate:
\[ \text{Unit rate} = \frac{\text{Total Cost}}{\text{Total Ounces}} = \frac{3.20}{64} \]
Now perform the division:
\[ \frac{3.20}{64} = 0.05 \]
So, the unit price per ounce is $0.05.
The correct response is $0.05.