<p>Okay I don't understand why today's question:</p>
<p>In just a couple of years, low-carbohydrate diets have accomplished what the government has failed to do in decades of trying: [it has convinced the public of refined grains, that they] are bad and whole grains are good.</p>
<pre><code>(A) it has convinced the public of refined grains, that they
(B) convincing the public about refined grains, which
(C) convince the public that refined grains
(D) convinces the public of refined grains, they
(E) convincing the public that refined grains
</code></pre>
<p>I picked E, because it sounds the best, but the correct answer is C. Why?</p>