David, the quiz slide submit button is programmed automatically to jump to the next slide as soon as it's clicked if there are no feedback layers. So your triggers never get a chance to run. Additionally, the trigger for A is linked to Shape A, while the B-D are linked to the Sumit button. This looks odd.
Also, it's probably not an issue, but there's no reason to use a plus sign for positive numbers. If you're assigning a positive value to the field,
CloudSet('A', '5'); should suffice (without "+" before 5).