To find the unit rate of deliveries per hour, you can divide the total number of deliveries by the total number of hours.
So, the calculation would be:
\[ \text{Unit Rate} = \frac{16 \text{ deliveries}}{4 \text{ hours}} = 4 \text{ deliveries per hour} \]
However, the options you've provided (A: 444, B: 222, C: 777, D: 888) do not include the correct unit rate. The correct answer should be 4 deliveries per hour. If you need help with something else, let me know!