In the first transition series,the highest $B.P.$ and $M.P.$ is of

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: In $T \ell I_{3}$,isomorphous to $CsI_{3}$,the metal is present in $+1$ oxidation state.
Reason $R$: $T \ell$ metal has fourteen $f$ electrons in the electronic configuration.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which one of the following properties is not a property of transition elements?

Which of the following oxides has the maximum basicity?

Which of the following general configurations of the outermost shell represents the chromium element [$Cr$'s atomic number $= 24$]?

Which of the following types of metals form the most efficient catalysts?