Given averages = 2, 5, 8, 11, 14, 17, 20, 23, 26, 29

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)

= 2+5+8+11+14+17+20+23+26+29

= 155

Total number of values(N)= 10

Substituting these values we get (A),

 $= \frac{155}{10}=15.5$

Hence, Option A is correct.