How can you make a payment method store entire credit card numbers?

A.
For security reasons, there are no native ways for doing that.

B.
Pass the credit card number to the payment method: it will be stored automatically.

C.
Change the protected property of payment method $_canSaveCc to true.

D.
Configure your method to save the card number by setting 1 to the following xpath: default/payment/
_NAME_/save_cc