Which cargo grade(s) are permitted by regulations to be carried on a barge in tanks fitted only with gooseneck vents and flame screens?

Correct Answer: Option D — D or E

Title 46 CFR regulations permit tank barges equipped only with gooseneck vents and flame screens to transport exclusively Grade D and E combustible liquids. These higher flashpoint cargoes do not generate flammable vapor concentrations under normal ambient conditions requiring specialized P/V valve protection.