Utilize the input text as a context reference, choose the right relationship between 'Aer Lingus' and 'Dublin' from the options.
Options: parent organization, platform, original broadcaster, location of formation

Adding Aer Lingus to its portfolio of airlines - British Airways, Iberia and Spanish budget carrier Vueling - opens a new avenue of growth for IAG, allowing it to expand capacity on lucrative transatlantic routes by using Dublin Airport.
location of formation