Peter Atherton, analyst at Jefferies investment bank, said that the cost to take control of just the UK assets of companies, which include British Gas owner Centrica and network operator National Grid, would drain about £124bn from the nation's coffers.
Refer to the input text as context and select the correct relationship between 'Centrica' and 'British Gas' from the available options.
Options: owner of, parent organization, business division, operator