feedback.php

<?php 

 if($question_data["user_answer_entry"][0] !="" && $question_data["question_right_answer"][0] != $question_data["user_answer_entry"][0]):

        $feedback = get_post_meta( $question_data["ID"], '_answer_feedback', true );
        // Check if the custom field has a value.
        if ( ! empty( $feedback ) ) {

        ?>

            <div class="alert alert-warning" role="alert" style="font-size: 14px;max-width: 70%;padding: 7px;line-height: 20px;">
              <?php echo "<b>Atenção:</b> ", $feedback; ?>
            </div>

<?php

        }

endif;

if($question_data["user_answer_entry"][0] !="" && $question_data["question_right_answer"][0] == $question_data["user_answer_entry"][0]):

?>

<div class="alert alert-success" role="alert" style="font-size: 14px;max-width: 70%;padding: 7px;line-height: 20px;">
              <?php echo "<b>Parabéns:</b> Você assinalou a alternativa correta."; ?>
            </div>

<?php endif; ?>

<hr>