There are two kinds of analysis: qualitative and quantitative
In quantitative we analyse the amount of something that is how much of something is present / the quantity. Ex: the length of branch of tree, number of students in class, volume of a liquid in a beaker.
In qualitative analysis we determine the kind of substance / quality of substance / nature of substance.
like: colour of a substance, odor of a substance or taste (bitter / sour / sweet etc) of a substance
So answer is : B.The substance tastes bitter