Utilize the input text as a context reference, choose the right relationship between Warburg Pincus and investment from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

A Warburg Pincus spokesperson said the firm was bound by internal operational policies, which didn't allow discussion of investment activities.

Answer: industry