Which two code fragments should you use at line n1, ind…

You are developing a banking module. You have developed a class named ccMask that has a maskcc method.
Given the code fragment:

You must ensure that the maskcc method returns a string that hides all digits of the credit card number except
the four last digits (and the hyphens that separate each group of four digits).
Which two code fragments should you use at line n1, independently, to achieve this requirement?

A.
Option A

B.
Option B

C.
Option C

D.
Option D