When the Show Correct Answer checkbox is checked it provides two features:
1. Trainees who have no more attempts left on the question will be presented with an "Answers" button (if they have not selected the correct answer). Clicking the "Answers" button will reveal the correct answer.
2. Trainers are presented with an "Explanation of correct answer" box for each question. This box allows the trainer the explain the reasoning behind the correct answer. This explanation will show up either after the trainee selects the correct answer or after they have run out of attempts it will show up when they click the "Answer" button. This will not show up in the course preview for Trainers.