test.cs

public static string GetAnswer(string chunk, string question)
{
  // create a prompt
  string prompt = $"```{chunk}```Your source is the information above. What is the answer to the following question? ```{question}```";

  // create a request object
  Request apiRequest = new Request
  {
    Messages = new[]
    {
      new RequestMessage
      {
         Role = "system",
         Content = "You should help to find an answer to a question in a document."
      },
      new RequestMessage
      {
         Role = "user",
         Content = prompt
      }
    }
  };

  // get the response
  if (GetResponse(apiRequest) is Response response)
  {
    // return the answer
    return response.Choices[0].Message.Content;
  }

  // return null if the response is null
  return null;
}