Which of the following contains a vague pronoun reference?
A: Lisa asked Annie to volunteer at the event, so her absence today is a surprise.
B: Lisa asked Annie to volunteer at the event, so Annie's absence today is a surprise.
The first answer choice contains a vague pronoun reference. The pronoun her could refer to Lisa's or Annie's.
The second answer choice shows a possible correction for the vague pronoun reference. Her has been replaced with Annie's.
Lisa asked Annie to volunteer at the event, so Annie's absence today is a surprise.