a
since the carbonyl carbon is electron deficient, so most susceptible to attack by nucleophilic reagents or base. A base increases the acidity of hydrogen atom attached to the \(\alpha-C\) of the ketones or aldehydes. That-why \(\alpha\) -hydrogen is easily abstracted from ketones by a base, e.g. in aldol condensation reaction, \(\alpha\) -hydrogen atom of aldehyde or ketone is abstracted by a strong base.