Identify the subject in the sentence: "The children played outside."

The correct answer is "The children" because the subject of a sentence indicates who or what is performing the action of the verb. In this example, "played" is the action occurring, and "the children" refers to the individuals carrying out that action. Therefore, "the children" is the noun phrase that serves as the subject of the sentence, clearly identifying who is involved in the activity of playing.

Other options do not serve as the subject; "played" is a verb describing the action, "outside" is an adverb indicating where the action takes place, and "the" is an article that modifies the noun "children." Each of these elements plays a distinct role in the sentence's structure, but only "the children" fulfills the function of the subject.