Which of the following is the forward exchange transaction ( )

A、The customer agreed with the bank that he has the right to purchase 1 million US dollars within one month at the exchange rate of 1 US dollar =6.6339 RMB;
B、The customer purchased 1 million US dollars from the bank at the exchange rate of 1 US dollar =6.6339 RMB and made the delivery on the second business day;
C、The customer purchased 1 million US dollars according to the standard quantity and month rules stipulated by the Futures Exchange;
D、The customer purchased 1 million US dollars from the bank at the exchange rate of 1 US dollar =6.6339 RMB and agreed to make the delivery after 15 days