Consider the following carbocations. What is the relative stability order of these carbocations?
$(1)$ $CH_3O-C_6H_4-CH_2^+$
$(2)$ $C_6H_5-CH_2^+$
$(3)$ $CH_3-C_6H_4-CH_2^+$

Arrange the following carbanions in the decreasing order of stability:
$I. \ p-Br-C_6H_4-CH_2^-$
$II. \ C_6H_5-CH_2^-$
$III. \ p-CH_3O-C_6H_4-CH_2^-$
$IV. \ p-CHO-C_6H_4-CH_2^-$
$V. \ p-CH_3-C_6H_4-CH_2^-$
Choose the correct answer from the options given below:

Which of the following has an unstable enol form?

The order of decreasing stability of the carbanions is:
$1.$ $(CH_3)_3C^-$
$2.$ $(CH_3)_2CH^-$
$3.$ $CH_3CH_2^-$
$4.$ $C_6H_5CH_2^-$

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:

Which is the most stable cation?