Gadolinium has a low value of third ionisation enthalpy because of $......$

The correct order of spin-only magnetic moment (in $BM$) for $Mn^{2+}$,$Cr^{2+}$,and $Ti^{2+}$ ions is:

Given below are two statements:
Statement $I :$ The $E^{\circ}$ value of $Ce^{4+} / Ce^{3+}$ is $+1.74 \, V$.
Statement $II :$ $Ce$ is more stable in $Ce^{4+}$ state than $Ce^{3+}$ state.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which of the following elements is found in the human body?

Which of the following oxides has the maximum basicity?

Which of the following cations in their respective oxidation states develops a colorless aqueous solution?