Who of the following is NOT a 20th century American poet?

A、<span style="font-size: 16px;font-family: &#39;Times New Roman&#39;, serif">Ezra Pound&nbsp; &nbsp;</span>

B、<span style="font-size: 16px;font-family: &#39;Times New Roman&#39;, serif">Amy Lowell&nbsp;</span>

C、<span style="font-size: 16px;font-family: &#39;Times New Roman&#39;, serif">Edgar Allan Poe&nbsp; &nbsp;</span>

D、<span style="font-size: 16px;font-family: &#39;Times New Roman&#39;, serif">Robert Frost</span>