The correct answer is: B. describes.
A dictionary is a book or electronic resource that lists the words of a language (typically in alphabetical order) and gives their meaning, or gives the equivalent words in a different language, often also providing information about pronunciation, origin, and usage.
A dictionary does not prescribe usage, meaning that it does not tell people how to use words. Instead, it describes how words are used. This is important because language is constantly evolving, and dictionaries need to reflect that evolution. If a dictionary were to prescribe usage, it would quickly become outdated.
The other options are incorrect because they do not accurately describe the role of a dictionary. Option A, “prescribes,” is incorrect because a dictionary does not tell people how to use words. Option C, “decides,” is incorrect because a dictionary does not dictate how words should be used. Option D, “imbibes,” is incorrect because a dictionary does not absorb or take in usage.