Observe the following oxides. The number of amphoteric oxides from the given list is
$CO, B_2O_3, SnO_2, PbO_2, Ga_2O_3, SnO, PbO, CO_2$

The characteristics of elements $X$,$Y$ and $Z$ with atomic numbers,respectively,$33$,$53$ and $83$ are :

The first $\left( \Delta_{i}H_{1} \right)$ and the second $\left( \Delta_{i}H_{2} \right)$ ionization enthalpies (in $kJ \ mol^{-1}$) and the $\left( \Delta_{eg}H \right)$ electron gain enthalpy (in $kJ \ mol^{-1}$) of a few elements are given below:

Elements	$\left( \Delta_{i}H_{1} \right)$	$\left( \Delta_{i}H_{2} \right)$	$\left( \Delta_{eg}H \right)$
$I$	$520$	$7300$	$-60$
$II$	$419$	$3051$	$-48$
$III$	$1681$	$3374$	$-328$
$IV$	$1008$	$1846$	$-295$
$V$	$2372$	$8581$	$+48$
$VI$	$738$	$1451$	$-40$

Which of the above elements is likely to be:
$(a)$ the least reactive element.
$(b)$ the most reactive metal.
$(c)$ the most reactive non-metal.
$(d)$ the least reactive non-metal.
$(e)$ the metal which can form a stable binary halide of the formula $MX_{2}$ ($X =$ halogen).
$(f)$ the metal which can form a predominantly stable covalent halide of the formula $MX$ ($X =$ halogen)?

Given below are two statements:
Statement $I$: Chlorine can easily combine with oxygen to form oxides,and the product has a tendency to explode.
Statement $II$: Chemical reactivity of an element can be determined by its reaction with oxygen and halogens.
In the light of the above statements,choose the correct answer from the options given below.

How does the metallic and non-metallic character vary on moving from left to right in a period?

$Be$ and $Al$ resemble in: