Utilize the input text as a context reference, choose the right relationship between 'Centrica' and 'British Gas' from the options.
Options: headquarters location, distribution format, brand, owner of

The competition watchdog said in March that it had granted permission for British Gas Trading (BGT) - a subsidiary of Centrica (LSE: CNA.L - news ) , the UK's biggest energy supplier - and Northern Powergrid to appeal against Ofgem's price control decision.
owner of