Which of the following contains a vague pronoun reference?

 - If Ron doesn't know how to make homemade waffles, he can find the recipe in the cookbook.
 - If Ron doesn't know how to make homemade waffles, he can find it in the cookbook.
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 recipe.
If Ron doesn't know how to make homemade waffles, he can find the recipe in the cookbook.