How is an EUI-64 format interface ID created from a 48-bit MAC address?

How is an EUI-64 format interface ID created from a 48-bit MAC address?

A.
by appending 0xFF to the MAC address

B.
by prefixing the MAC address with 0xFFEE

C.
by prefixing the MAC address with 0xFF and appending 0xFF to it

D.
by inserting 0xFFFE between the upper three bytes and the lower three bytes of the MAC
address

E.
by prefixing the MAC address with 0xF and inserting 0xFafter each of its first three bytes

Explanation: