The answer you are looking for is B.Oil
Answer:
B > Voluntary trade involves two parties, both of which agree freely to making a trade
Answer:
led to the spread of slavery
Explanation:
Generally in Brazil, the biggest factor influencing racial categorization is directly linked to economic rather than physical characteristics. Brazil was the last country to abolish slavery in 1888, the country still has a strong racial problem, as most black people live in slums and suburbs. Despite being a racially mixed country, black people are still marginalized.