In $0\mathrm{.}10MKCN,$ the chemical species with the highest concentration $($except $H_{2}O)$ is

A$.N{a}^{+}.$

B$.C{N}^{-}.$

C$.H_3{O}^{+}($or $($:$H^{+}\}.$

D$.O{H}^{-}.$

E$.K^{+}.$