Which of the following is an example of a preposition?

The correct choice is "above," which is a preposition. Prepositions are words that link nouns, pronouns, or phrases to other words within a sentence, often indicating relationships in terms of time, place, direction, or manner.

In this case, "above" indicates a spatial relationship, suggesting that something is at a higher level or position relative to something else. For example, in the sentence "The book is above the table," "above" clearly denotes the position of the book in relation to the table.

The other choices do not function as prepositions. "Run" is a verb that describes an action, "quickly" is an adverb modifying verbs and actions to describe how they are performed, and "beautiful" is an adjective that describes a noun by attributing qualities. Thus, "above" stands out as the only option that fulfills the definition and function of a preposition within a sentence.