Identify the sentence that contains a vague pronoun reference. a) when toni morrison was fifty seven, her novel beloved won the pulitzer prize. b) when she was fifty seven, toni morrison’s novel beloved won the pulitzer prize. c) francine received many awards for her work and earned over $3 million, but she was very modest about her achievements. d) i have no doubt that the world renowned author, dennis benson was an energetic man who led a busy life filled satisfying experiences and adventures.