<p>The question:</p>
<p>(As) children mature, they develop (an independence) that their parents, who (have been)
A B C
responsible for them since they were born, often find difficult (to accept). (No error)
D E</p>
<p>The correct answer is E "No Error" and I don't understand why B "an independence" is grammatically correct. Shouldn't independence be plural because the subject, children, is plural?</p>