In the context of the input sentence, determine the relationship between 'Aer Lingus' and 'Dublin'.
Options: original broadcaster, parent organization, platform, 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