The standard (IEEE 802) format for printing()in human-friendly form is six groups of two hexadecimal digits, separated by hyphens (-) or colons (:), in transmission order, e.g.01-23-45-67-89-ab, 1:23:45:67:89:ab. This form is also commonly used for EUI-64.
A.hard disk logical block address
B.IP address
C.mail address
D.MAC address