The correct answer is B) a sounding tape gage using blue chalk. The reason is that sounding tape gages using chalk are not an acceptable means to measure liquid levels in cryogenic cargo tanks. Cryogenic cargo tanks operate at extremely low temperatures, which would make the use of a sounding tape with chalk impractical and unreliable. Instead, the acceptable means to measure liquid levels in cryogenic cargo tanks include a nitrogen bubbler system, a capacitance level measurement system, or a radar gage, as listed in options A, C, and D.