The spin only magnetic moment of $Mn^{4+}$ ion is nearly (in $BM$)

Stainless steel does not rust because

Elements of $d$-block are called

In which of the following is variable valency observed?

Given below are two statements:
Statement $I$: $Cr^{2+}$ is oxidising and $Mn^{3+}$ is reducing in nature.
Statement $II$: $Sc^{3+}$ compounds are repelled by the applied magnetic field.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which one of the elements with the following outer orbital configurations may exhibit the largest number of oxidation states?