Which of the following contains a vague pronoun reference?

 - After Mary discussed the new research methods with Laura, she decided to try some of them out.
 - After discussing the new research methods with Laura, Mary decided to try some of them out.
The second answer choice contains a vague pronoun reference. The pronoun she could refer to Mary or Laura.
After Mary discussed the new research methods with Laura, she decided to try some of them out.
The first answer choice shows a possible correction for the vague pronoun reference. The text has been rewritten so that the meaning is clear.
After discussing the new research methods with Laura, Mary decided to try some of them out.