What is true about the future of favelas?

Câu hỏi: Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 30 to 34.
Around the world, Rio de Janeiro is famous for its beautiful beaches, and Carnival celebration. But the city is also known for its poor areas, known as favelas. For years, many favelas had high poverty and crime rates. However, things are starting to change.
In the past, many favelas received very little government assistance. Neighbourhood residents had to build their own streets and homes. Gangs were also common, and so were guns. However, a new government plan is starting to change this. The city is sending thousands of police officers into favelas with the goal of driving out the gangs. In some favelas, the plan is already working. Crime is down, and unlike the past, children are playing in the streets again. New apartment buildings are being built, and the city is providing more services. "In 20 years," says police officer Leonardo Nogueira, "the children who live here now will be different people."
Police influence is changing the favelas, but something else is, too. Today, more Brazilians are moving into these neighbourhoods because housing is expensive in other parts of Rio. "Favelas are a place for young doctors without money to get started and young architects to start working," explains Simone Miranda, a Rio tour guide. In the past, favela residents felt different - separate from the rest of Rio. "But now," says Miranda, "they feel part of the society of Brazil."
Life is improving in the favelas, but there are still challenges. In some areas, poverty rates are still high. As students, families, and foreigners move into the favelas, property costs skyrocket. In some areas, housing has more than doubled in price. Despite this, favela residents are hopeful. If Rio can develop these favelas for all residents - both poor and middle class the city could become a model for other cities with similar problems.
What is true about the future of favelas?
A. They will set a good example about dealing with urban problems.
B. They will provide cheap residence for the poor and middle class.
C. They face both advantages and drawbacks.
D. Foreigners won't move into favelas because of high crime rates.