<p>Doctors are trying to figure out how to make sure everyone at risk receives a flu shot, and they are calling on federal health department authorities to launch more vigorous public awareness campaigns. </p>
<p>I am stuck between these two answers:</p>
<p>(A) Doctors are trying to figure out how to make sure everyone at risk receives a flu shot, and they </p>
<p>(B) Doctors trying to figure out how to make sure everyone at risk receives a flu shot </p>
<p>According to the book, the answer is B but isn’t B wrong because the statement “trying to figure out how to make sure everyone at risk receives a flu shot” should be a parenthetical statement and thus should have commas before and after it?</p>
<p>Thanks!</p>