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