In the context of the input sentence, determine the relationship between 'BG Group' and 'Royal Dutch Shell'.
Options: distribution format, parent organization, position held, owner of

Energy companies took the most points off the index, with Royal Dutch Shell (Xetra: R6C1.DE - news ) and BG Group (LSE: BG.L - news ) closing down 3 and 1.8 percent respectively.
parent organization