  üí° Most basic usage of <code>d3.arc()</code>
        </div>
        <hr />
        <p>
          The <code>d3.arc()</code> function is here to create the content of
          the <code>d</code> parameter of the <code>path</code> element. When
          you call <code>d3.arc()</code>, it returns a function that we call a
          generator.
        </p>
        <p>
          This generator is the function we dreamed of! It accepts an object
          with 4 properties and return the path we need. T