Which of the following orders is correct for the property mentioned in brackets?

Based on the provided image, identify the correct option for the elements $A, B, C, D, E$ given that $C$ has the electronic configuration $[Xe] \ 6s^2 \ 5d^1$.

Which of the following statements is incorrect?

Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?
$(a)$ Valence principal quantum number $(n)$
$(b)$ Nuclear charge $(Z)$
$(c)$ Nuclear mass
$(d)$ Number of core electrons.

Consider the following:
$(I)$ The order of first ionisation enthalpy of the first three elements of the $3^{rd}$ period is $Mg > Al > Na$
$(II)$ The element with an electronegativity of $3.5$ is chlorine
$(III)$ The order of sizes of ions $Mg^{2+}, Na^{+}, F^{-}$ and $O^{2-}$ is $Mg^{2+} < Na^{+} < F^{-} < O^{2-}$
$(IV)$ The $IUPAC$ name of the element with atomic number $106$ is Bohrium.
The correct statements are

Nitrogen has positive electron gain enthalpy whereas oxygen has negative. However,oxygen has lower ionisation enthalpy than nitrogen. Explain.