Which of the following orders of ionization energy is correct?

Explain the trend observed in ionisation enthalpy when moving from top to bottom in the same group of the periodic table.

The successive ionization enthalpy values for an unknown element are $\Delta_i H_1 = 899 \ kJ/mol$,$\Delta_i H_2 = 1757 \ kJ/mol$,$\Delta_i H_3 = 14847 \ kJ/mol$,and $\Delta_i H_4 = 17948 \ kJ/mol$. To which group of the periodic table does this element belong?

If first ionization enthalpies of element $X$ and $Y$ are $419 \ kJ \ mol^{-1}$ and $590 \ kJ \ mol^{-1}$,respectively and second ionization enthalpies of $X$ and $Y$ are $3069 \ kJ \ mol^{-1}$ and $1145 \ kJ \ mol^{-1}$,respectively. Then the correct statement is :-

Which of the following elements has the highest first ionization enthalpy?

Which of the following statements is incorrect?