The general order of reactivity of carbonyl compounds for nucleophilic addition reactions is

The reaction of $A$ to give $B$ and $C$ as shown in the reaction scheme is an example of:
$CH_2=CH_2$ $\xrightarrow[2. Zn/H_2O]{1. O_3} A$ $\xrightarrow{Conc. NaOH} B + C$
(Where $B$ is an alcohol and $C$ is a sodium salt of a carboxylic acid)

Which of the following compounds will most readily be dehydrated to give an alkene under acidic conditions?

The major product '$A$' formed in the above reaction is:

Given below are two statements:
Statement $I:$ The boiling points of aldehydes and ketones are higher than hydrocarbons of comparable molecular masses because of weak molecular association in aldehydes and ketones due to dipole-dipole interactions.
Statement $II:$ The boiling points of aldehydes and ketones are lower than the alcohols of similar molecular masses due to the absence of $H$-bonding.
In the light of the above statements,choose the most appropriate answer from the options given below:

Arrange the following compounds in increasing order of their enol content:
$1. CH_3CHO$
$2. CH_3COCH_3$
$3. CH_3COCH_2CHO$
$4. CH_3COCH_2COCH_3$