A: they freed the slaves who converted to Islam.
Use the process of elimination. It would be illegal in Muslim law to have children with slaves unless you married them, so C would not be an option.
Native Americans were not in Asia, so neither is D.
Muslims don't believe in forcing religions upon others, and it wouldn't make sense to force Christianity upon someone when you're not Christian, so B is not an option.
A is the answer.
The sharia law states:
Free Muslims, but note that:
Slaves who convert to Islam are not automatically freed
Children born to legally enslaved Muslims are also slaves
This means a slave who converted to Islam would be freed, but not automatically.
