What is the relationship between Ryanair and Michael O'Leary 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.

Michael O'Leary has insisted he would be at the controls of Ryanair for years to come and scotched suggestions the Irish airline's financial success could trigger takeover interest.

Answer: chief_executive_officer