UIViewController的dismiss跳转多个页面

有多个控制器，依次通过  presentViewController: animated:completion: 方法进行页面跳转，那么如何从最后一个视图控制器跳转会根控制器呢？

假设有四个视图控制器，每个控制器中都有一个UIButton，UIButton的响应方法，依次为

根控制器：

- (void) buttonClicked:(id) sender {
    A_Controller * controller =[[A_Controller alloc] init];
    [self presentViewController: controller animated:YES completion:nil];
}

A控制器：

- (void) buttonClicked:(id) sender {
    B_Controller * controller =[[B_Controller alloc] init];
    [self presentViewController: controller animated:YES completion:nil];
}

B控制器

- (void) buttonClicked:(id)sender {
    C_Controller * controller = [[C_Controller alloc] init];
    [self presentViewController:controller animated:YES completion:nil];
}

C控制器

- (void) buttonClicked:(id) sender {
    UIViewController * controller = self.presentingViewController;
    [self dismissViewControllerAnimated:YES completion:^{
        UIViewController * c = controller.presentingViewController;
        [controller dismissViewControllerAnimated:YES completion:^{
            [c dismissViewControllerAnimated:YES completion:nil];
        }];
    }];
}

这样，点击C控制器button的响应方法的时候，就会跳会到根控制器