Which of the following contains a vague pronoun reference?
A: When Emily was researching the lives of famous scientists, it said that Albert Einstein had a speech impediment when he was a child.
B: When Emily was researching the lives of famous scientists, one source said that Albert Einstein had a speech impediment when he was a child.
The second answer choice contains a vague pronoun reference. The pronoun it is used without its antecedent.
The first answer choice shows a possible correction for the vague pronoun reference. It has been replaced with one source.
When Emily was researching the lives of famous scientists, one source said that Albert Einstein had a speech impediment when he was a child.