a grammar problem,,,need help!

<p>well i just met this question that confused me a lot</p>

<p>The Bronte Myth,Lucasta Miller's study of the three British novelists,attempts to trace the historical route by which Charlotte and Emily Bronte(and ,to a less degree,Anne)became popular cultural icons.
A:attempts
B :by which
C to a less degree
D popular
E No error</p>

<pre><code>I chose E but the answer is C, what is wrong with " to a less degree"

</code></pre>

<p>Can somebody help me with this??
thanx......:)</p>

<p>should be: to a lesser degree</p>