The orbital picture of a singlet carbene $(:CH_2)$ can be drawn as:

The most stable carbonium ion is:

Match the ions given in Column-$I$ with their nature given in Column-$II$.

Column-$I$	Column-$II$
$A$. $CH_3-O^{+}=CH-CH_3$	$1$. Stable due to resonance
$B$. $F_3C^{+}$	$2$. Destabilised due to inductive effect
$C$. $(CH_3)_3C^{-}$	$3$. Stabilised by hyperconjugation
$D$. $CH_3-CH^{+}-CH_3$	$4$. $A$ secondary carbocation

Arrange the following carbocations in decreasing order of stability:
$I: CH_3-CH_2^+$
$II: (CH_3)_2CH^+$
$III: Ph-CH_2^+$

Identify the correct order of stability of the following carbocations:

Determine the decreasing order of stability for the following carbocations: $(I) \ CH_3-C^+(CH_3)-CH_3$,$(II) \ CH_3-CH^+(OCH_3)$,$(III) \ CH_3-CH^+(COCH_3)$.