Which of the following contains a vague pronoun reference?

 - Lucy felt awful after she scolded Erica for missing the deadline.
 - After Lucy scolded Erica for missing the deadline, she felt awful.
The first answer choice contains a vague pronoun reference. The pronoun she could refer to Lucy or Erica.
After Lucy scolded Erica for missing the deadline, she felt awful.
The second answer choice shows a possible correction for the vague pronoun reference. The text has been rewritten so that the meaning is clear.
Lucy felt awful after she scolded Erica for missing the deadline.