Identify the alkyne in the following sequence of reactions,

Step-by-step solution

In Wacker process, alkene is oxidised into aldehyde. Since on ozonolysis, only alkenes produce aldehydes, ' A ' must be an alkene. To decide the structure of alkene that undergoes ozonolysis, bring the products together in such a way that O atoms are face to face and, replace O by double (=) bond. Thus, Therefore, alkyne must be