46 CFR Subchapter T requires that rigid plastic or other nonmetallic piping __________.

Correct Answer: Option D — All of the above

46 CFR Subchapter T mandates strict controls on nonmetallic piping to prevent fire and flooding hazards. These materials are restricted to non-vital systems, must utilize approved metallic fittings at bulkhead penetrations to maintain structural integrity, and are strictly prohibited in fuel systems due to potential melting or degradation risks.