Utilize the input text as a context reference, choose the right relationship between Castrol and BP from the options. Options: 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.

BBS Engineering offers services to most of the active oil companies in Ghana and is the main representative for Castrol BP lubricants and Sealite UK Ltd (Marine Navigation Aids) in the country.

Answer: parent_organization