What is the relationship between 'Singapore Airlines' and 'Singapore' in the context of the input sentence.
Options: operator, parent organization, headquarters location, brand

Airbus Launches New Ultra-Long Range Version of the A350-900 Enables Singapore Airlines to resume non-stop flights to the US Singapore Airlines (SIA) has selected Airbus' newly launched Ultra-Long Range version of the A350-900 for non-stop flights to the US.
headquarters location