A. w3-corner
B. w3-rounded
C. w3-round
D. w3-border-radius

Solution

B. w3-rounded

Explanation

<p><span style="white-space:pre"> </span></p><table class="table table-bordered"><tbody><tr><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;"><b>Class</b></span></td><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;"><b>Description</b></span></td></tr><tr><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">w3-round</span><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px; white-space: pre;"> </span></td><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">Adds small rounded corners</span></td></tr><tr><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">w3-round-small</span></td><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">Adds slightly rounded corners</span></td></tr><tr><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">w3-round-large</span></td><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">Adds larger rounded corners</span></td></tr><tr><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">w3-round-xlarge</span></td><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">Adds extra-large rounded corners</span></td></tr><tr><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">w3-round-xxlarge</span></td><td><span style="color: rgb(0, 0, 0); letter-spacing: 0.14px;">Adds very large rounded corners</span></td></tr></tbody></table><p><span style="white-space:pre"> </span></p>