Let three consecutive even numbers be x, x+2, x+4

According to the question

$$\begin{gathered} = \mathrm{x}+\mathrm{x}+2+\mathrm{x}+4-\frac{ \mathrm{x}+\mathrm{x}+2+\mathrm{x}+4}{3}=68 \\ =3x+6-\frac{3x+6}{3}=68 \\ =3x+6-\frac{3\left(x+2\right)}{3}=68 \end{gathered}$$

= 3x+6-x-2= 68

= 2x+4= 68

= 2x= 64

X=32

So, the 3 consecutive even numbers are

x =32

x+2=34

x+4 =36

The middle number = 34

Hence, Option B is correct.