Yesterday, Bill stopped at the library to pick up some books for his father. When he got to the library, the librarian could not find the books. She looked for them for half an hour. (4) She was embarrassed when she found that they had been put back on the shelves. a.) two possesive singular pronouns and one personal plural pronoun b.) a personal pronoun and two possessive pronouns c.)two personal pronouns and one possessive pronoun d.) three personal subject pronouns