The correct answer is - C. It was based on plantation agriculture, where slaves served as a labor force.
Brazil's economy in the period between 1650 to 1880 was mostly based around large plantations, part of which for the home market, part consisted of cash crops. The size of the plantations was very large, thus they needed a lot of workers. The work force was consisted largely of slaves that were bought from the African continent. Unlike the Western countries, Brazil was very slow and late in its industrialization, which set it back for quite some time.