$\begin{array}{1 1}(a)\;\text{3-hydroxybutanoic acid,adipic acid}\\(b)\; \text{3-hydroxypentanoic acid,adipic acid}\\(c)\;\text{3-hydroxypentanoic acid,3-hydroxybutanoic acid}\\(d)\;\text{3-hydroxypentanoic acid,styrene}\end{array}$
