Oil major BP PLC BP., +6.04% BP, +5.98% tacked on 6%, Royal Dutch Shell PLC RDSB, +4.67% RDS.B, +3.60% rose 4.7% and BG Group PLC BG., +4.10% moved up 4.1%.
Analyze the relationship between 'BG Group' and 'Royal Dutch Shell' within the context of the input sentence.
Options: headquarters location, creator, parent organization, legal form