First Federal S & L has an online real-time system, with terminals installed in all of its branches. This system will not accept a customer’s cash withdrawal instructions in excess of \($1,000\) without the use of a “terminal audit key.” After the transaction is authorized by a supervisor, the bank teller then processes the transaction with the audit key. This control can be strengthened by

a. Increasing the dollar amount to $1,500.

b. Online recording of the transaction on an audit override sheet.

c. Requiring manual, rather than online, recording of all such transactions.

d. Using parallel stimulation.