$CH_3-C(CH_3)_2-CH_2-CH_2^+ \to CH_3-C^+(CH_3)-CH(CH_3)-CH_3$
How many $H^-$ shifts are involved in the above rearrangement?

In the above reaction,the left-hand side and right-hand side rings are named as '$A$' and '$B$' respectively. They undergo ring expansion. The correct statement for this process is:

Match the List-$I$ with List-$II$:

$A$. Carbocation	$I$. Species that can supply a pair of electrons.
$B$. Carbon free radical	$II$. Species that can receive a pair of electrons.
$C$. Nucleophile	$III$. $sp^2$ hybridized carbon with empty $p$-orbital.
$D$. Electrophile	$IV$. $sp^2/sp^3$ hybridized carbon with one unpaired electron.

Choose the correct answer from the options given below:

Correct order of stability is

Arrange the following carbanions in the decreasing order of their stability: ${(CH_3)_3}C^-$,$CCl_3^-$,${(CH_3)_2}CH^-$,${C_6H_5}CH_2^-$.

Based upon an understanding of product stability,predict the product formed when the following dianion reacts with one equivalent of acid $(H^+)$.