Which of the following elements does not belong to the family of elements indicated?

Under ambient conditions,the total number of gases released as products in the final step of the reaction scheme shown below is:

Inert gases have positive electron gain enthalpy. Its correct order is

Assertion $(A)$: All noble gases are monoatomic.
Reason $(R)$: All noble gases have very low melting and boiling points.

Which factor is most responsible for the increase in boiling point of noble gases from $He$ to $Xe$ $:-$

Given below are two statements:
Statement-$I$: Noble gases have very high boiling points.
Statement-$II$: Noble gases are monoatomic gases. They are held together by strong dispersion forces. Because of this,they are liquefied at very low temperatures. Hence,they have very high boiling points.
In the light of the above statements,choose the correct answer from the options given below: