What is the relationship between A350 and Singapore Airlines in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

Singapore Airlines is the largest customer for the A350 XWB in East Asia, with deliveries of its 67 aircraft now on order starting in the first quarter of 2016.

Answer: operator