Which of the following statements is not true?
a. "who" and "whom" are personal pronouns.
b. "whom" is an object pronoun.
c. "who" is a subject pronoun.
d. "whom" can serve as the object of a preposition.

The answer is A. who and whom are personal pronouns

The answer is "he was bad enough in all conscience, but the devil himself could not temp him to turn slave-trader. satirical is a synonym for sarcastic. so when the author says that tom walker could not be tempted by the devil he does not literally mean "the devil" but he means that he is too morally upright to become a slave-trader.