What Potential Problem Exists in This Table Structure

Multiple Choice

What potential problem exists in this table structure?

A) The "fact rule" is violated if more than one account is at the same bank.
B) The "fact rule" is violated if more than one account has the same account balance.
C) The "fact rule" is violated if more than one bank has the same address.
D) All of the above are potential problems.
E) None of the above are potential problems.