Final answer:
The correct option is c) "I saw him at the store.", where "him" is the correct direct object pronoun. Options a, b, and d have incorrect pronoun usage, where subjective pronouns are mistakenly used as objects.
Step-by-step explanation:
The question asks which sentence correctly uses the direct object pronoun. The correct sentence is c) "I saw him at the store." Here, "him" is the direct object pronoun that receives the action of the verb "saw". In sentences a and b, "she" and "he" are incorrectly used as objects; the correct object pronouns should be "her" and "him" respectively. In sentence d, "she" is also incorrectly used; the correct pronoun should be "her".
Direct object pronouns receive the action of the verb and are essential in constructing clear and grammatically correct sentences. An understanding of pronoun case is important for proper pronoun usage, distinguishing between subjective case (used as subjects) and objective case (used as objects).