Answer: B) The word “that” is an adjective describing which one.
Explanation: the word "that" is used to represent the person, thing, or idea indicated, mentioned, or understood from the situation. In a sentence, it can function as a pronoun, as a determiner (or adjective), an adverb or a conjunction. In the given sentence we can see an example of the use of the word "that" as an adjective that modifies the noun "piece of information" by describing which one.
