Answer:
D) permit limited private ventures
Step-by-step explanation:
In a command economy the government decides how to allocate resources, and they generally do not do it very well.
In a mixed economy that favors free markets, the market (suppliers and consumers) can decide how to allocate resources, at least in a limited way. So country B would probably be willing to allow private companies, even foreign private companies, to start trading (exporting and importing goods).