# A new carbon-carbon bond formation is possible in

$\begin{array}{1 1}(a)\;\text{Schotten-Baumann reaction}&(b)\;\text{Reimer -Tiemann reaction}\\(c)\;\text{Williamson synthesis}&(d)\;\text{Above all}\end{array}$

A new carbon-carbon bond formation is possible in Reimer -Tiemann reaction only
Hence (b) is the correct answer.