In the following paragraph, the fourth sentence contains 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. two possessive singular pronouns and one personal plural pronoun a personal pronoun and two possessive pronouns two personal pronouns and one possessive pronoun three personal subject pronouns

can you be a bit more specific

in the following paragraph, the fourth sentence the correct answer is: three personal subject pronouns

”she was embarrassed when she found that they had been put back on the shelves…”

a   subject pronoun is a personal pronoun. i, you, he, she it, we, they.  

in the sentence it can be observed she, used twice and they used once. is for this reason that is a three personal subject pronoun sentence.

you didn't list the options but im guessing it's resolving contradictions

this question is grammatically incorrect and is illegible to me so i can not answer.