Order of conductivity of `Li^+,Na^+,K^+,Rb^+,Cs^+` in aqueous medium

Moar conductivites of Li^(+),Na^(+),K^(+) "and" Rb^(+) ions in aqueous solutions are in the following order.

Give reason for decreasing order of conductivity of following Cs^(+) gt Rb^(+) gt K^(+) gt Na^(+) gt Li^(+)

Select the compound having maximum conductivity in aqueous medium.

The CORRECT order of the mobility of the alkali metal ions in aqueous solution is A) Rb^+ > K^+ > Na^+ > Li^+ B) Li^+ > Na^+ > K^+ > Rb^+ C) Na^+ > K^+ > Rb^+ > Li^+ D) K^+ > Rb^+ > Na^+ > Li^+

Mixture containing aqueous Li^+,Na^+ , K^+ ions are electrolysed . Cations are discharged at cathode in the order : (easiest at the end) M^(+) (aq) +e^(-) rarrM