Who must approve the carriage of a liquefied gas not appearing in table 4 of 46 CFR Part 154?

Correct Answer: Option B — Commandant (G-MTH)

According to 46 CFR Part 154, the carriage of any liquefied gas not specifically listed in Table 4 requires explicit engineering and operational approval from the USCG Commandant (G-MTH) due to novel hazard considerations.