Step 1: Concept
Tannins are complex organic compounds classified into hydrolysable and condensed types.
Step 2: Meaning
Hydrolysable tannins are esters of a sugar (usually glucose) with one or more trihydroxybenzene carboxylic acids.
Step 3: Analysis
When these tannins are hydrolyzed by acids or enzymes like tannase, they break down into their constituent parts, which include gallic acid or ellagic acid. Condensed tannins, by contrast, form phlobaphenes.
Step 4: Conclusion
Therefore, ellagic acid is a characteristic product of the hydrolysis of certain hydrolysable tannins.
Final Answer: (B)