Which of the Following Absolute Thresholds for Taste Is Correct

Multiple Choice

Which of the following absolute thresholds for taste is correct?

A) Detecting a gram of salt dissolved in five gallons of water
B) Detecting a difference in tastes between two spots on the tongue, one-eighth of an inch apart
C) Detecting one teaspoon of sugar dissolved in two gallons of water
D) Detecting a teaspoon of vinegar mixed in with two gallons of water
E) Detecting the sweetness of a fruit while blindfolded