read the sentence.\nallie considered it carefully, and ______ decided to train for the marathon…

Brief Explanations:

• Objective pronouns (e.g., me, him, her) are used as objects of verbs or prepositions. In the sentence, the blank is part of the subject - verb structure ("______ decided"), so an objective pronoun is not suitable.
• Subjective pronouns (e.g., I, he, she) are used as subjects of sentences. But we already have "Allie" as the subject. The use of "herself" later in the sentence gives a clue that it's not just a simple subjective pronoun.
• Intensive pronouns (e.g., myself, yourself, himself, herself) are used to emphasize the noun or pronoun they refer to. In the sentence "Allie considered it carefully, and ______ decided to train for the marathon herself", "herself" is used to emphasize that Allie made the decision on her own.
• Reflexive pronouns (e.g., myself, yourself, himself, herself) are used when the object of a verb or preposition refers to the same person or thing as the subject. Here, the action of "decided" is not reflecting back on the subject in the way reflexive pronouns typically function (e.g., "She hurt herself" - the action of hurting reflects back on the subject).

Answer:

intensive