Utilize the input text as a context reference, choose the right relationship between 'Boeing' and 'United Launch Alliance' from the options.
Options: subsidiary, business division, owner of, employer

Aerojet Vice President Julie Van Kleeck declined comment on reports that Aerojet has offered $2 billion to acquire United Launch Alliance (ULA), a 50-50 rocket launch venture of Lockheed Martin Corp and Boeing Co.
owner of