Refer to the input text as context and select the correct relationship between 'Boeing' and 'United Launch Alliance' from the available options.
Options: employer, owner of, business division, subsidiary

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