Explanation

Bisphenol A (BPA) is an industrial organic chemical used primarily as a core monomer in the synthesis of polycarbonate plastics and epoxy resins.

– Polycarbonate is a tough, transparent engineering plastic widely used in reusable beverage bottles, food storage containers, tableware, safety glasses, and medical instruments.
– BPA also lines the interior coating of metal food cans and municipal water pipes.
– Residual unpolymerized BPA molecules can leach into foods and drinks, raising serious health concerns as an endocrine-disrupting compound that mimics natural estrogen.

For a clear visual breakdown of plastic categories (including BPA/polycarbonate under Category 7), watch this helpful guide: Different Types of Plastics Explained (Plascon Plastics).

Therefore, BPA is a key structural building block in polycarbonate — Option B.