Answer
Option B is correct.
Walking rate = 2 (2/3) miles per hour.
Explanation
To answer this, we need to first note that
1 hour = 60 minutes
So, we have
[tex]\begin{gathered} \frac{\frac{2}{3}\text{mile}}{15\text{ minutes}}\times\frac{60\text{ minutes}}{1\text{ hour}} \\ =\frac{2}{3}\times4 \\ =\frac{8}{3} \\ =2\frac{2}{3}\text{ miles per hour} \end{gathered}[/tex]Hope this Helps!!!