A clue to BA's lingering love affair with the 747 lies in the model's ability to eke out capacity from scarce operating slots at its London Heathrow hub at a time when lower fuel prices make retaining older planes an option.
Refer to the input text as context and select the correct relationship between 'Heathrow hub' and 'London' from the available options.
Options: publisher, headquarters location, founded by, distributed by