To solve this problem, we need to analyze the motion of the block on the inclined plane.$\\$Given:$\\$• The block starts from rest, so initial velocity $u = 0. \\$• The motion is uniformly accelerated due to gravity along the incline.$\\$The distance $S_n$ traveled by the block in the $n$-th second is given by:$\\ S_n = u + \frac{1}{2} a (2n - 1) \\$Since $u = 0,$ this simplifies to:$\\ S_n = \frac{1}{2} a (2n - 1) \\$Similarly, the distance $S_{n+1}$ traveled in the $(n+1)$-th second is:$\\ S_{n+1} = \frac{1}{2} a (2(n+1) - 1) \\ S_{n+1} = \frac{1}{2} a (2n + 1) \\$Now, we need to find the ratio $\frac{S_n}{S_{n+1}}: \\ \frac{S_n}{S_{n+1}} = \frac{\frac{1}{2} a (2n - 1)}{\frac{1}{2} a (2n + 1)} \\$The $\frac{1}{2} a$ terms cancel out, leaving:$\\ \frac{S_n}{S_{n+1}} = \frac{2n - 1}{2n + 1} \\$Therefore, the ratio $\frac{S_n}{S_{n+1}}$ is $\frac{2n-1}{2n+1}. \\$This corresponds to Option 2.