Which of the following would be classified as grade "C" petroleum product?

Correct Answer: Option A — Reid vapor pressure of 5 psia, flash point of 70°F.

Under 46 CFR 30.10-22, Grade C liquids have a Reid vapor pressure (RVP) of 8.5 psia or less and a flash point of 80°F or below. Option A fits these criteria, as 5 psia is below 8.5 and 70°F is below the 80°F threshold for Grade C classification.