MCQ
For any integer $k$, let $\alpha_k=\cos \left(\frac{k \pi}{7}\right)+i \sin \left(\frac{k \pi}{7}\right)$, where $i=\sqrt{-1}$. The value of the expression
$\frac{\sum_{k=1}^{12}\left|\alpha_{k+1}-\alpha_k\right|}{\sum_{k=1}^3\left|\alpha_{4 k-1}-\alpha_{4 k-2}\right|}$ is
- A$1$
- B$2$
- C$3$
- ✓$4$