Answer:
b. specialize in.
Step-by-step explanation:
When is about production and national economy, Nations most of the time specialize in industries which are advantageous for them. For example, if the country is rich in oil, they will specialize in oil, if the country is rich in silver, they will specialize around it. This is an strategy to ensure a economical stability in the country. Imagine that a Nation specialize in copper, which its main source is from another country, they will depend on them always, because they don't have copper mines at all.