Question: The reaction of Wolff-Kishner is one: 
 Options:  <1> Oxidation of carbonyls to give acids. <2> Reduction of carbonyls to alcohols. <3> Deoxygenation of carbonyls that takes place in an acid medium. <4> Deoxygenation of carbonyls that is carried out in an alkaline medium. <5> Carbonyl deoxygenation performed in neutral medium.
4