In the MAC address 00:90:69:9F:EA:46 what represents the Organizationally Unique Identifier (OUI)?

In the MAC address 00:90:69:9F:EA:46 what represents the Organizationally Unique Identifier (OUI)?

A.
69:9F:EA:46

B.
00:90:69:9F

C.
9F:EA:46

D.
00:90:69