Here is a table with information about some students: And a ToDo list transaction based on Joe earning an A in a 4 credit class. Start transaction Add 4 credits to Joe Change Joe's GPA to 3.66 End transaction A) Why are the actions not idempotent? What could go wrong if we crash midway through the list? B) Rewrite the todo list so that the actions are idempotent: How does a rollback allow a deadlock to be resolved? Which of the three conditions for deadlock does it eliminate