Given averages =5, 7, 13, 0, 15

We know the formula,

 $\mathrm{Average} \left(\mathrm{A}\right)=\frac{\mathrm{Sum} \mathrm{of} \mathrm{given} \mathrm{values} \left(\mathrm{S}\right)}{\mathrm{Total} \mathrm{number} \mathrm{of} \mathrm{values} \left(\mathrm{N}\right)}$

 Here,

 Sum of given values(S)

= 5+7+13+0+15

= 40

Total number of values(N)= 5

Substituting these values we get (A),

 $= \frac{40}{5}=8$

Hence, Option B is correct.