<li>Many changes occured while she was president of the college; these changes increased its educational quality and effectiveness</li>
<li>Many changes occured while she was president of the college; these changes increased both the educational quality and effectiveness of the college.</li>
</ol>
<p>The answer says sentence 2 is correct and sentence 1 is not because it involves a VAGUE pronoun “it”</p>
<p>My question is how do you judge if a pronoun is “vague” or not? To me the pronoun is perfectly clear in sentence 1 because college is the only singular thing mentioned in the entire sentence (president here should be referred to by “she”), so the “it” here must refers to the college. Who can teach me the rule~~~?</p>