Here's why:
* Conjunctions connect words, phrases, or clauses. "And" specifically joins items of equal grammatical rank.
* Example: "I ate pizza and ice cream." ("Pizza" and "ice cream" are nouns of equal rank.)
Let's look at why it's not the other options:
* Prepositions show the relationship between a noun or pronoun and another word in the sentence. They often indicate location, time, or direction.
* Example: "The book is on the table." ("On" shows the relationship between "book" and "table".)
* Linking verbs connect the subject of a sentence to a predicate nominative (a noun that renames the subject) or predicate adjective (an adjective that describes the subject).
* Example: "She is happy." ("Is" links the subject "She" to the predicate adjective "happy".)
* Pronouns replace nouns.
* Example: "He went to the store." ("He" replaces a specific person's name.)