Analyze the relationship between 'Airbus' and 'aircraft' within the context of the input sentence.
Options: subsidiary, owner of, product/material produced, owned by

“We believe the magnitude of our 2005 and 2011 aircraft orders helped us to negotiate favourable terms with Airbus and our other aircraft-related suppliers and service providers, which provide us with a structural cost advantage by reducing the overall costs associated with the acquisition, maintenance and operation of our aircraft,” IndiGo said in the prospectus.
product/material produced