Considering the above reactions, the compound ' A ' and compound ' B ' respectively are

Step-by-step solution

Groups like cyanides and nitrites possess two nucleophilic centres and are called ambident nucleophiles. Actually cyanide group is a hybrid of two contributing structures and therefore can act as a nucleophile in two different ways [ - C ≡ N   ↔   : C = N - ] , i.e., linking through carbon atom resulting in alkyl cyanides and through nitrogen atom leading to isocyanides. KCN is predominantly ionic and provides cyanide ions in solution. Although both carbon and nitrogen atoms are in a position