Which of the following contains a vague pronoun reference?

 - Bruce felt better about collaborating on the research project after Ted talked with him about it.
 - After Ted talked with Bruce about the research project, he felt better about collaborating on it.
The first answer choice contains a vague pronoun reference. The pronoun he could refer to Ted or Bruce.
After Ted talked with Bruce about the research project, he felt better about collaborating on it.
The second answer choice shows a possible correction for the vague pronoun reference. The text has been rewritten so that the meaning is clear.
Bruce felt better about collaborating on the research project after Ted talked with him about it.