Peggy Drinks Some Distilled Water with a Small Amount of Vinegar

Multiple Choice

Peggy drinks some distilled water with a small amount of vinegar in it. What would she have to be able to do in order for us to conclude that she has crossed the absolute threshold?

A) detect that there is something added to the water
B) identify the taste as "sour"
C) identify the taste as "vinegar"
D) all of the above