(N/A) Oxidation: Oxidation of alcohols involves the breaking of $O-H$ and $C-H$ bonds to form a carbon-oxygen double bond $(C=O)$.
$(b)$ Dehydrogenation: In this process,$C-H$ and $O-H$ bonds break to release dihydrogen $(H_2)$,hence it is called a dehydrogenation reaction.
$(c)$ Oxidation of $1^o$ alcohols: $1^o$ alcohols are oxidized to aldehydes,which are further oxidized to carboxylic acids using strong oxidizing agents like $KMnO_4$.
$(d)$ Oxidation of $2^o$ alcohols: $2^o$ alcohols are oxidized to ketones using oxidizing agents like $CrO_3$.
$(e)$ Oxidation of $3^o$ alcohols: $3^o$ alcohols are resistant to oxidation under normal conditions but undergo dehydration to form alkenes in the presence of hot concentrated $H_2SO_4$ or by heating with copper at $573 K$.