Which of the following ions is paramagnetic?

In the electronic configuration of which of the following elements is an electron arranged in the $5d$ orbital?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$: The first ionization enthalpy of $3d$ series elements is more than that of group $2$ metals.
Reason $(R)$: In $3d$ series of elements,successive filling of $d$-orbitals takes place.
In the light of the above statements,choose the correct answer from the options given below:

Where are the transition elements and inner transition elements located in the periodic table?

From $+6$ to $+1$ oxidation state is shown by the element of ....... group.

Among the following pairs of ions,the lower oxidation state in aqueous solution is more stable than the other in: