Final answer:
Fuyao's profitability was not due to a reduction in worker protections for health benefits, as unions do not typically support such measures. Restricting migration is often due to fears of wage suppression among less skilled domestic workers.
Step-by-step explanation:
The Chinese company Fuyao Glass Industry Group was able to become profitable despite higher wages in America for reasons except one. The correct reason which did not contribute to their profitability is "b- the worker union reduced worker protections for additional health benefits." Unions typically aim to protect workers' rights and increase benefits, not reduce protection for benefits. In fact, Fuyao faced criticism for their labor practices.
Regarding the main reason for restricting the migration of workers to a high-wage industrial country, option "c- the fear that immigrants from low-wage countries will drive down wages for a country's own less skilled workers" is the most accurate. This aligns with concerns that global competition may drive down wages of low-skilled workers.