From the above question

we apply VBODMAS rule,

$= 13\frac{3}{7}+18\frac{1}{14}+8\frac{3}{4}$

(Add the whole and fraction parts separately)

$$\begin{gathered} = \left(13+18+8\right)+\left(\frac{3}{7}+\frac{1}{14}+\frac{3}{4}\right) \\ = 39+\frac{5}{4} \end{gathered}$$

(Convert the improper fraction to a mixed number)

$=39+1\frac{1}{4}$

(Separate the mixed number)

$$\begin{gathered} =39+1+\frac{1}{4} \\ =40+\frac{1}{4} \end{gathered}$$

Hence, option D is correct.