Utilize the input text as a context reference, choose the right relationship between 'BG Group' and 'Royal Dutch Shell' from the options.
Options: chief executive officer, member of, stock exchange, parent organization

Merger and acquisition activity in the energy sector has been rekindled as company valuations slumped along with oil prices, highlighted by Royal Dutch Shell (Xetra: R6C1.DE - news ) 's $70 billion bid to acquire BG Group (LSE: BG.L - news ) earlier this year.
parent organization