Take context from the input text and decide on the accurate relationship between 'Boeing' and 'United Launch Alliance' from the options provided.
Options: employer, subsidiary, owner of, business division

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