ORGANIC(M.S. A & K-49(B))

b) is the ans

TsOH ABSTRACTS H+...O^- ATTACHES ITSELF TO C OF CARBONYL GRP IN HCHO....WHILE THE O^-OF HCHO ATTACHES TO C OF CH⁺-OH....FUTHER HEATING KICKS OUT OH...AND B IS WHAT U GET

@MKM: DUE TIME DEFICIT I CUD NOT PUT UP THE DIAGRAM...SRY FOR THAT....I LL DO THAT NEXT TIME

nucleophilic addition and then hemiacetal will form ,which will again undergo nucleophilic attack