The security question answer session variable should just be: <?php echo($_SESSION["random_answer"]); ?>
So line 13 should read:
$WAFV_Errors .= WAValidateLE((strtolower(isset($_POST["General_Questions_group_2_Security_Question_2"])?$_POST["General_Questions_group_2_Security_Question_2"]:"")) . "",($_SESSION["random_answer"]). "",true,3);