Well, if you are genuinely worried about terminology you can call that what it is, the "white slave trade". It's ancient, extensive, and completely, 100 percent, not taught in schools. So there's a lesson there too.
b. I'm sure there are people who would be offended by the term you used too. If everything is potentially offense, then at a certain point it becomes very hard to say anything, even if you're trying to stop slavery.