Concept:The present perfect tense is formed with has/have plus the past participle form of the verb.Explanation:The sentence uses has bought and …Here, has is the auxiliary verb, so both verbs joined by and must be in the past participle form.Bought is the past participle of buy.The past participle of eat is eaten.Options ate, eats, and eating are not past participles, so they do not fit after has.Therefore, the correct verb form is eaten.Answer:C. eaten