Refer to the input text as context and select the correct relationship between 'Vikram Pandit' and 'Citigroup' from the available options.
Options: product/material produced, employer, owner of, brand

Last week, Citigroup Inc's ( C.N ) Chief Executive Vikram Pandit said that he, Chairman Win Bischoff, and senior adviser Robert Rubin would not receive bonuses for 2008.
employer