Question

People tend to place the public welfare above their own self-interest. in contrast, ___ people will exploit anyone for a profit—they will even sell harmful products.

Answer 1

The answer would be: Alturistic-Mercenary
Alturistic people refers to someone who put a huge attention towards the well being of other people around them. Therefore, they will be more likely to like huge public welfare.
Mercenary people tend to think that everybody is responsible for their own well-being, therefore they're driven to do what they're doing.