Step 1: Understand that a noun names a person, place, thing, or idea.
Step 2: In option (B), the word betters refers to people who are superior or more capable, which makes it a noun.
Step 3: Examine the other options:
In (A), better is used as an adjective (comparative degree).
In (C), better is used as a verb (to improve).
In (D), better is used as an adverb.
Step 4: Therefore, the sentence where better is used as a noun is option (B).