Utilize the input text as a context reference, choose the right relationship between Deloitte and audit 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.

Santander has picked PwC to carry out one of the most lucrative audit contracts in banking, ending a relationship with Deloitte that last year generated almost €90m (£63.9m) in fees.

Answer: product_or_material_produced