Which of the following contains a vague pronoun reference?

 - The GPS said to turn left at the fork and then continue straight for three miles.
 - It said to turn left at the fork and then continue straight for three miles.
The first answer choice contains a vague pronoun reference. The pronoun it is used without its antecedent.
The second answer choice shows a possible correction for the vague pronoun reference. It has been replaced with the GPS.
The GPS said to turn left at the fork and then continue straight for three miles.