Match the carbocations in List I with the main stabilising factor in List II. List I: (P) $(CH X_{3}) X_{3} C X^{+}$ ; (Q) $CH X_{3} - O - CH X_{2} X^{+}$ ; (R) $C X_{6} H X_{5} - CH X_{2} X^{+}$ ; (S) $CH X_{2} = CH - CH X_{2} X^{+}$ . List II: (1) donation of an oxygen lone pair into the empty p orbital; (2) delocalisation of charge into an aromatic ring; (3) delocalisation over two carbons through an adjacent C=C; (4) hyperconjugation with nine C-H bonds.

AP-4, Q-1, R-2, S-3
BP-4, Q-1, R-3, S-2
CP-1, Q-4, R-2, S-3
DP-2, Q-1, R-4, S-3

Answer: A

(CH X_{3}) X_{3} C X^{+}

is stabilised by hyperconjugation with nine C-H bonds (P-4).

CH X_{3} - O - CH X_{2} X^{+}

is stabilised by the oxygen lone pair (Q-1). The benzyl cation is delocalised into the ring (R-2), and the allyl cation shares charge over two carbons through the C=C (S-3).

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Answer: A

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