The chairmen of FTSE 100 engineering giant Babcock International (LSE: BAB.L - news ) , British Land (LSE: BLND.L - news ) and the AA have put their names to an open letter from Heathrow chairman Sir Nigel Rudd urging ministers to support expansion of the west London airport.
Take context from the input text and decide on the accurate relationship between 'Babcock International' and 'London' from the options provided.
Options: chairperson, brand, headquarters location, distribution format