If $i = \sqrt{-1}$, the value of the integral

$$\oint_{c}\dfrac{7z + i}{z(z^2 + 1)}dz \quad\quad\quad\quad|z|<2$$,

using the cauchy residue theorem is

1. $2\pi i$
2. $0$
3. $-6\pi$
4. $6\pi$