Which of the following carbocations lacks hyperconjugative stability?

The stable carbocation formed in the reaction of benzene with $n$-propyl chloride in the presence of anhydrous $AlCl_3$ is:

$A$ certain reaction occurs in two steps as:
$(i)$ $2 SO_{2(g)} + 2 NO_{2(g)} \rightarrow 2 SO_{3(g)} + 2 NO_{(g)}$
$(ii)$ $2 NO_{(g)} + O_{2(g)} \rightarrow 2 NO_{2(g)}$
In the reaction,

Arrange the following carbocations in decreasing order of stability.

Which of the following compounds gives the same carbocation on ionization?

Which of the following carbocations is the most stable?