Incorrect method of preparation for alcohols from the following is:

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Given: The question asks for the incorrect method of preparation of alcohols.

Find: Which option does not prepare an alcohol.

Evaluate each method using the solution discussion:

Ozonolysis of alkene cleaves the $\text{C=C}$ bond and gives carbonyl compounds such as aldehydes or ketones, not alcohols.

\text{CH}_2=\text{CH}_2 \xrightarrow{\text{O}_3} \text{C}=\text{O} + \text{C}=\text{O}

So this is not a method for preparing alcohols.

Hydroboration-oxidation of alkene gives an alcohol.
Reaction of alkyl halide with aqueous NaOH gives alcohol by nucleophilic substitution.

\text{R-X} + \text{NaOH} \rightarrow \text{R-OH} + \text{NaX}

Reaction of ketone with RMgBr followed by hydrolysis gives an alcohol after Grignard addition.

\text{R}_2\text{C}=\text{O} + \text{RMgBr} \xrightarrow{\text{H}_2\text{O}} \text{R}_2\text{C(OH)R}

Therefore, the incorrect method is Ozonolysis of alkene. The correct option is A.

The provided solution shows option D, but its own explanation concludes that ozonolysis of alkene is the incorrect method. Hence the derived answer is A.

Given: Four methods are listed for preparation of alcohols.

Find: The method that is incorrect.

Option A: Ozonolysis of alkene breaks the double bond and forms aldehydes or ketones. It does not normally prepare alcohols.
Option B: Hydroboration-oxidation converts an alkene into an alcohol, so this is correct.
Option C: Alkyl halide with aqueous NaOH undergoes substitution to form alcohol, so this is correct.
Option D: Ketone with $\text{RMgBr}$ followed by hydrolysis forms an alcohol, so this is correct.

Thus only Option A is incorrect.

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