Which of the following contains a vague pronoun reference?

 - After Tyler graduates, he plans to travel around Europe with his brother.
 - Tyler plans to travel around Europe with his brother after he graduates.
The first answer choice contains a vague pronoun reference. The pronoun he could refer to Tyler or his brother.
Tyler plans to travel around Europe with his brother after he graduates.
The second answer choice shows a possible correction for the vague pronoun reference. The text has been rewritten so that the meaning is clear.
After Tyler graduates, he plans to travel around Europe with his brother.