Take context from the input text and decide on the accurate relationship between 'BG Group' and 'Royal Dutch Shell' from the options provided.
Options: chief executive officer, stock exchange, member of, 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