A vessel of 500 gross tons constructed in 1980 must have a fixed container under each fuel oil tank vent, overflow, and fill pipe. What is the minimum required capacity of that container?

Why B is correct

33 CFR §155.320(a)(1) requires a ship of 300 or more but less than 1600 gross tons constructed after June 30, 1974 to have a fixed container of at least one-half barrel capacity. A 500 GT vessel built in 1980 falls squarely in this category. The one-barrel requirement applies only to vessels of 1600 GT or more.