Which will show maximum non-metallic character?

$Be$ and $Al$ show similarities in properties due to diagonal relationship except in the property $X$ given below. What is $X$?

Red hot carbon will remove oxygen from the oxides $XO$ and $YO$ but not from $ZO$. $Y$ will remove oxygen from $XO$. Use this evidence to deduce the order of activity of the three metals $X, Y$ and $Z$ putting the most active first.

Considering the elements $F,$ $Cl,$ $O,$ and $N,$ the correct order of their chemical reactivity in terms of oxidizing property is:
$(a)$ $F > Cl > O > N$
$(b)$ $F > O > Cl > N$
$(c)$ $Cl > F > O > N$
$(d)$ $O > F > N > Cl$

In the modern periodic table,the acidic nature of oxides:

Which element from the following possesses half-filled $d$-orbitals either in expected or in observed electronic configuration?