The correct answer is - C. favelas.
The favelas are makeshift communities in Brazil. They are located on the edges of the cities, usually the larger ones. Aproximately one third of the residents of the cities live in the favelas.
This type of communities have initially been formed by soldiers, but over time have become the places where the poor people live. The infrastructure is not in good condition, the living conditions on relatively low level, and the population density is incredibly high. Unfortunately, the crime flourishes in this communities because the people are poor and do not choose means as to how to get to bigger profit.