Which of the following transition metals is considered the softest?

Which of the following paramagnetic ions would exhibit a magnetic moment (spin only) of the order of $5 \ BM$?
(At. Nos. $Mn = 25$,$Cr = 24$,$V = 23$,$Ti = 22$)

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 of the following cations has the lowest spin-only magnetic moment?

Which of the following is ferromagnetic in nature?

Which of the following ions has the highest magnetic moment?