Analyze the relationship between 'Russell Group' and 'London' within the context of the input sentence.
Options: owner of, headquarters location, owned by, legal form

* Rolls-Royce's biggest shareholder ValueAct is in for the long haul Elsewhere, the London Stock Exchange Group began to reap the benefits of acquiring the Russell Group , as robust growth in the index business helped Europe’s oldest independent bourse post a 27pc rise in half-year adjusted operating profit to £366.1m.
headquarters location