The table below shows the number of cakes Stella baked with respect to time.

To find the unit rate of cakes baked per hour, we need to determine how many cakes Stella bakes in one hour.

From the table, we can see at 10 hours, Stella baked 15 cakes. To find the unit rate:

1. Calculate the rate of cakes per hour:
\[
\text{Cakes per hour} = \frac{\text{Total cakes}}{\text{Total hours}} = \frac{15 \text{ cakes}}{10 \text{ hours}} = 1.5 \text{ cakes per hour}
\]

Now, let's analyze each statement provided:

A. Stella baked 2 cakes in each hour.
**Incorrect.** The calculation shows she baked 1.5 cakes per hour.

B. Stella baked 3 cakes in each hour.
**Incorrect.** Again, the calculation shows she baked 1.5 cakes per hour.

C. Stella took of an hour for each cake.
**Incomplete and unclear.**

D. Stella took hours for each cake.
**Incorrect.** The calculation shows she took 2/3 of an hour for each cake (which is 1.5 cakes per hour).

Since none of the options reflect the correct unit rate of 1.5 cakes per hour, the most accurate way to express the unit rate from the calculation is that **Stella baked 1.5 cakes in each hour.**

If we had to offer a choice from the options provided, none represent the correct unit rate.