Based on the code above, list the number, name, and available credit for all customers with credit ...

Based on the code above, list the number, name, and available credit for all customers with credit limits that exceed their balances.
 a. SELECT CustomerNum, CustomerName AS AvailableCredit FROM Customer WHERE CreditLimit>Balance ;
  b. SELECT CustomerNum, CustomerName, CreditLimit AS AvailableCredit FROM Customer WHERE CreditLimit>Balance ;
  c. SELECT CustomerNum, CustomerName, Balance AS AvailableCredit FROM Customer WHERE CreditLimit>Balance ;
  d. SELECT CustomerNum, CustomerName, CreditLimit-Balance AS AvailableCredit FROM Customer WHERE CreditLimit>Balance ;