From the following given statements
i) $\mathrm{O}$.... $\mathrm{H}$ hydrogen bond length is more
ii) The ionic bond strength of $\mathrm{CsF}$ is less than that of $\mathrm{NaF}$.
iii) The number of electrons present in all inner shells of sodium atom are 10. The correct combination is

(i) Hydrogen bond length of $\mathrm{O}-\mathrm{H}$ is more than covalent bond length because strength of covalent bond is more than that of hydrogen bond.
(ii)ionic bond is most effective between the most electropositive atom and most electronegative atom. So $\mathrm{CsF}$ has more strength than $\mathrm{NaF}$
(iii) in $\mathrm{Na}$ the total electrons are 11 but in $\mathrm{Na}$ ion it has 10 electrons.

Hence , the correct option is (D).only i and iii are correct.