title: Bot Framework- Why Choice hold CardAction, and what is the role of each?
body: <p>I use <em>Bot Framework v4</em>, and I try to use <code>ChoicePrompt</code> for the menu.</p>
  
  <p>I'm trying to create a <code>Choice</code> object, and I see that it contains a <code>CardAction</code> object.</p>
  
  <p>Because <code>CardAction</code> has more options, such as a <code>value</code> that is an <code>object</code> type rather than a <code>string</code> type, I want to use it.</p>
  
  <p>But even if I assign a value to the <code>CardAction</code> <code>value</code> field, I get an <strong>error</strong> because <code>Choice</code> must get a value in its <code>value</code>, which is the value obtained <strong>at the end</strong>.</p>
  
  <p>So why does the <code>Choice</code> contain a <code>CardAction</code> object? What is everyone's job?</p>