Refer to the input text as context and select the correct relationship between 'Deloitte' and 'audit' from the available options.
Options: legal form, stock exchange, distribution format, product/material produced

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.
product/material produced