Step 1: Recall that a noun is a word used to name a person, place, thing, or idea. To answer the question, we must determine which of the given words performs this naming function. Understanding the basic definition of a noun helps eliminate words that belong to other parts of speech.
Step 2: Examine each option carefully:
- north — refers to a direction or region, which is a place. Since it names a place or concept related to location, it functions as a noun.
- but — is used to join words or clauses and shows contrast; therefore, it is a conjunction.
- not — modifies verbs, adjectives, or other adverbs to express negation; hence, it is an adverb/particle.
- adapt — expresses an action, meaning “to change or adjust,” so it is a verb.
Step 3: After classifying each word according to its grammatical function, we conclude that the only word that names a place or concept and therefore acts as a noun is north.