 " 4 @-@ D " first aired in the United States on December 9 , 2001 . The episode earned a Nielsen household rating of 5 @.@ 1 , meaning that it was seen by 5 @.@ 1 % of the nation 's estimated households and was viewed by 5 @.@ 38 million households . " 4 @-@ D " was the 62nd most watched episode of television that aired during the week ending December 9 . The episode was later broadcast in the United Kingdom on BBC One in November 25 , 2002 . 
