Could you explain to me why the answer D is correct?

Thanks!

_| 23. A major difference between trade with increasing costs and trade with external scale economies is that: a. Consumers of imports lose with external scale economies and gain with increasing costs. b. Consumers of imports gain with external scale economies and lose with increasing costs. c. Consumers of exports lose with external scale economies and gain with increasing costs. (1. Consumers of exports gain with external scale economies and lose with increasing costs. ANSWER: D