title: How to get List<String> from JSON list using Retrofit 2?
body: <p>I am new to Android. I need to get a list of strings from a JSON list. It will be added to a <code>Spinner</code> list. I have the list on server like </p>
  
  <pre><code>[{"bgroup":"A+"},{"bgroup":"A1+"},{"bgroup":"A1-"}]. 
  </code></pre>
  
  <p>tried with Retrofit Scalars.
  Response  as </p>
  
  <pre><code>[{"bgroup":"A+"},{"bgroup":"A1+"},{"bgroup":"A1-"}]
  </code></pre>
  
  <p>but error detecting as:</p>
  
  <blockquote>
    <p>Expected a string but was BEGIN_OBJECT at line 1 column 3 path $[0]*</p>
  </blockquote>
  
  <p>Any better way to retrieve the list of strings from the JSON?</p>