Analyze the relationship between 'Bharti Airtel' and 'Vodafone' within the context of the input sentence.
Options: developer, manufacturer, owned by, parent organization

The de-linking of licences from spectrum wherein spectrum had to be bought in open auctions ensured that only serious operators remained in the game and led to a scenario where only three operators — Bharti Airtel , Vodafone India and Idea Cellular—consolidated their market position cornering around 75% of the subscriber market.
owned by