で「OK」ボタンを押すとUIAlertView元に戻りたい  のですUITableViewControllerが、クリックしても元に戻りません。
QuizViewController.h:
@interface QuizViewController : UIViewController <UIAlertViewDelegate> { 
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex;
@end
QuizViewController.m
-(IBAction)buttonWasClicked:(id)sender{
UIButton *resultebutton= (UIButton*)sender;
if (qCount < totalQuestions) {
    id prevQuestion =  [appDelegate.qs objectAtIndex:qCount-1];
    NSString * correctAns = [prevQuestion labelAns];
    if ([correctAns isEqualToString:resultebutton.titleLabel.text]) 
        myScore += 5;            
    NSLog(@"The button title is %@ ", correctAns);
    NSLog(@"The button title is %@ ", resultebutton.titleLabel.text);
    NSString *finishingStatement = [[NSString alloc] initWithFormat:@"Your score so far is %i!", myScore];
    theScore.text = finishingStatement;
    id nextQuestion = [appDelegate.qs objectAtIndex:qCount];
 quizLbl.text = [nextQuestion labelQn];
    headerLbl.text = [nextQuestion labelHeader];
 [qBtn setTitle:[nextQuestion labelBtn] forState:UIControlStateNormal];
 [qBtnB setTitle:[nextQuestion labelBtnB] forState:UIControlStateNormal];
 [qBtnC setTitle:[nextQuestion labelBtnC] forState:UIControlStateNormal];
 [qBtnD setTitle:[nextQuestion labelBtnD] forState:UIControlStateNormal];
 qCount++;
 }
 else {
     UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Results" message:[[NSString alloc] initWithFormat:@"Your total score will be %i!", myScore]
                                                    delegate:nil cancelButtonTitle:@"OK" otherButtonTitles: nil];
     [alert show];
 }
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    QuizTableViewController *quizTable = [self.storyboard instantiateViewControllerWithIdentifier:@"quizTable"];
    [self.navigationController presentModalViewController:quizTable animated:YES]; 
}