Which among the following compounds is a weakest base?

In the cell represented as $$\mathrm{Ni}_{(\mathrm{s})}\left|\mathrm{Ni}_{(\mathrm{IM})}^{2 \oplus}\right|\left|\mathrm{Ag}_{(\mathrm{IM})}^{\oplus}\right| \mathrm{Ag}_{(\mathrm{s})}$$, the reducing agent is

What is the value of intercept on $$y$$-axis when $$\log \frac{x}{m}$$ is plotted against $$\log P$$ in Freundlich isotherm?

Which from following statements is true for group 16 elements?