Not offering any sort of official advice here - you've got the right answer (to be honest). Some additional context from the immigration agent's perspective may be useful, though.

They want to screen out those with criminal motives .... but also those that could cause economic harm to their country.

"I'm here for business" is pretty vague. Maybe it works. But if pushed, "I'm here for meetings" is very different than "I'm here to train my team" or "I'm here to complete a project.". The second and third statement could imply that you or your company have elected to 'take' (true or not) work away from the local workforce. That may cast you in a bad light.