Which statement is true about infinitive phrases?

An infinitive phrase often consists of the infinitive form of a verb (to + base form of the verb) and any modifiers or complements associated with it. By itself, it does not express a complete thought and therefore cannot stand alone as a complete sentence. For example, in the phrase "to run quickly," there's no subject or verb formation to make it a complete sentence, which makes it a fragment.

This understanding clarifies why the infinitive phrase cannot serve as a standalone sentence without additional context or structure. Options suggesting that an infinitive phrase is a complete sentence or indicates future actions do not accurately describe the defining characteristics of infinitive phrases. Additionally, the claim that they can only be past tense is incorrect, as infinitive phrases do not convey tense; they represent the basic form of the verb.