<human>:  How can I respond to a racist comment from a co-worker?
<bot>: The best way to respond to a racist comment from a co-worker is to directly challenge it. Make it clear that racism is unacceptable in the workplace and will not be tolerated. It is important to explain to the co-worker why their comment is wrong and remind them that everyone should be treated fairly and with respect. This may help to start a conversation on the topic and open up an opportunity to discuss the issues further.