To anneal a copper gasket, you should heat the gasket __________.

Correct Answer: Option D — cherry red and quench in water

Annealing copper restores its ductility after work-hardening. Heating the copper to a cherry red color allows the crystalline structure to realign. Quenching in water immediately stops the process and prevents oxidation, leaving the metal soft and pliable, which is essential for creating a proper seal in flanged joints.