Why would a money market account require a minimum balance?
 A)the bank wants to make sure that only people with a lot of money use money market accounts
 B)the bank wants to protect customers from trying to write a check for more money than the account holds 
 C)the minimum balance is designed to keep too many people from asking for a money market account 
 D)a minimum balance lets a bank know how much money it can safely lend to other customers