Utilize the input text as a context reference, choose the right relationship between Centrica and British Gas 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.

As chief of staff, O’Kelly advises the CEO of British Gas parent Centrica (LSE: CNA.L - news ) .

Answer: owner_of