Which of the following is not used in the preperation of ketones?

Case: Read the passage and answer the following questions

Aldehydes and ketones are generally prepared by oxidation of primary and secondary alcohols. Dehydrogenation of alcohols gives aldehydes and ketones. Ozonolysis alkenes give aldehydes ketones or a mixture of both depending on the substitution pattern of the alkene. Aldehydes are prepared from acyl chloride, nitrile, esters and even from hydrocarbons by different kinds of oxidation. Ketones are prepared from benzene or its derivatives through Friedel-Crafts acylation reaction. Carboxylic acids are prepared from aldehydes and ketones on oxidation. Nitriles are hydrolysed to amides and then to carboxylic acids. It is even prepared using Grignard’s reagent.