text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE table_27713890_1 (production_code VARCHAR, us_viewers__millions_ VARCHAR)
  ### Question:
  What is the production code for the episode that had 23.9 million u.s. viewers?
  ### Answer:
  SELECT production_code FROM table_27713890_1 WHERE us_viewers__millions_ = "23.9"