Take context from the input text and decide on the accurate relationship between 'Betfair' and 'online gambling' from the options provided.
Options: brand, member of, industry, creator

On the upside, shares in mid-cap Betfair soared 17 percent after the online gambling company and Irish rival Paddy Power said they had reached an agreement in principle on a possible merger, marking the latest in a string of possible tie-ups across the sector.
industry