Are you familiar with Go? What advantages does it offer a programmer?

When asking this question, the interviewer is testing your knowledge of a specific technology that is likely in use within their operation. If the technology is a common one for your profession, you should know about it and be able to describe its function and advantages. If it is obscure or rarely used, it is OK to acknowledge that you don't know about it, and then describe how you would go about learning it.