Answer:
A. Use mutually exclusive classes.
Explanation:
From the given frequency distribution:
![\left|\begin{array}c$Number of Minutes &$Frequency\\-------&------\\$0 to less than 5 &6\\$5 to less than 10& 9\\$8 to less than 13 &14\\$13 to less than 18 &2\end{array}\right|](https://img.qammunity.org/2021/formulas/mathematics/college/vfoyk0khauevwx3towbb320ttq6fpisll4.png)
We can see that we have these class interval
- 5 to less than 10
- 8 to less than 13
The data in these two ranges will overlap and therefore violates the rule of mutual exclusivity.