The number of stereoisomers for $pent-3-en-2-ol$ is ...........

Which of the following structures is not meso-$2,3$-butanediol?

Indicate whether each of the following pairs are identical,enantiomers,or diastereomers?
$I$ || $II$ || $III$

Total number of stereo-isomers possible for the following compound is:
$1,2$-disubstituted cyclohexane with a $-\text{CH}_2\text{OH}$ group at position $1$ and a $-\text{CH}=\text{CH}-\text{CH}=\text{CH}-\text{CH}_2\text{CH}_3$ group at position $2$.

Find out the statements which are not true.
$A$. Resonating structure with more number of covalent bonds and lesser charge separation are more stable.
$B$. In electromeric effect, an unsaturated system shows $+E$ effect with nucleophile and $-E$ effect with electrophile.
$C$. Inductive effect is responsible for high melting point, boiling point and dipole moment of polar compounds.
$D$. The greater the number of alkyl groups attached to the doubly bonded carbon atoms, higher is the heat of hydrogenation.
$E$. Stability of carbanion increases with the increase in $s$-character of the carbon carrying the negative charge.
Choose the correct answer from the options given below.

Identify the name of the method used for the three-dimensional representation of the molecule as follows: