The tax-hailing app's Chinese unit currently operates in almost 20 cities, Mr Kalanick said at an event in Beijing held by Uber investor Baidu (Xetra: A0F5DE - news ) .
Refer to the input text as context and select the correct relationship between 'Baidu' and 'Beijing' from the available options.
Options: position held, headquarters location, product/material produced, owner of