On the Subject of Letter Keys

I haven't thought of anything yet...

See Appendix A for indicator identification reference.
See Appendix B for battery identification reference.

Follow these rules in the order they are listed. Perform the first action that applies:
  1. If the number indicated is equal to sixty-nine, Press the button with the label 'D'
  2. If the number indicated is divisible by six, press the button with the label 'A'
  3. If there are two or more batteries on the bomb and the number is divisible by three, press the button with the label 'B'
  4. If the Serial number contains a 'C' 'E' or '3' and the number is greater than or equal to twenty-two, and less than or equal to seventy-nine, then press the button labelled 'B'
  5. Otherwise, if the serial number contains a 'C' 'E' or '3', then press the button labelled 'C'
  6. If the indicated number is less than forty-six, then press the button labelled 'D'
  7. Otherwise, press the button labelled 'A'