Compare the carbon-carbon double bond rotation energy for the following compounds $A$,$B$,and $C$:

Arrange the following in the decreasing order of stability:
$I. CH_2=CH-CHO$
$II. ^+CH_2-CH=CH-O^-$
$III. ^-CH_2-CH=CH-O^+$

Draw other resonance structures related to the following structure and find out whether the functional group present in the molecule is ortho,para directing or meta directing.

Resonance effect is not observed in

Given below are two statements.
Statement $I :$ The dipole moment of $CH_3-CH=C(CH_3)-CH=O$ is greater than $CH_3-CH_2-CH_2-CH=O$.
Statement $II :$ $C_1-C_2$ bond length of $CH_3-CH=CH-CH=O$ is greater than $C_1-C_2$ bond length of $CH_3-CH_2-CH_2-CH=O$.
In the light of the above statements,choose the correct answer from the options given below $:$

Among the following,the antiaromatic compounds are: