Substance A is tested and found to have a pH of 3.
Substance B, a common food, tastes sour.
Substance C causes metals to corrode.
Substance D feels slippery in solution.
I am pretty sure that the no-acid substance is the last option from the scale represented above : Substance D feels slippery in solution. I choose this one beause I've recognized that it is a base which usually interact with oils in order to produce the same solution that was mentioned in the opton.
