What I would do is make the A, B and C paragraph items.  Then add
checkboxes (C-u C-c C-x C-b) to any list item you want to mark as a todo
item.  You can set/unset using C-c C-x C-b.  If you add the text [/] to
the headline with the TODO on it, it will be updated to indicate the
number of completed checkboxes and the total number of such boxes each
time you set or unset one.