As an add on.
You do NOT need a B visa to get a work permit. A non immigrant visa is the requirement. Don't care what a lawyer or immigration says.
I worked for years, various wp's all issued on my Non O based on being married.
If you are on B visa it ends when the job ends, and you get 7 days to leave. If you are on a Non O based on marraige it stays valid, til expiry date, at the end of the job.