Noble gases have very low boiling points. Why?

What is the percentage of $Argon$ in the air (in $\%$)?

The percentage of $Ar$ in dry air is approximately .......... $\%$. (in $\%$)

Which of the following is not correct for the given reaction sequence:
$XeF_6 + H_2O \rightarrow A + 2HF$
$XeOF_4 + H_2O \rightarrow B + 2HF$
$XeO_2F_2 + H_2O \rightarrow C + 2HF$

Least chemical activity is shown by

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: