Which one among the following is a transient or structural thermosetting plastic?

Bakelite (polyoxybenzylmethylenglycolanhydride) is a primary example of a thermosetting polymer. It undergoes chemical cross-linking upon heat application to form a three-dimensional networked structure that becomes permanently rigid and cannot be re-melted or reshaped, unlike thermoplastics such as Polyvinyl Chloride ($\text{PVC}$) and Polyvinyl Acetate ($\text{PVA}$).