Final answer:
Farming and cattle ranching are the most common activities in the Brazilian Highlands, greatly encouraged by economic policies and international demand. The correct option is option B.
Step-by-step explanation:
The most common activities in the Brazilian Highlands would likely be farming and cattle ranching. These activities are prevalent as the Brazilian government and international economic policies have historically encouraged the conversion of rainforest to pasture land and agricultural fields through tax cuts and incentives.
The demand for grains, edible oils, and beef, driven both by international markets and efforts to improve standards of living, has caused a significant increase in these practices.
While logging also occurs in the region, its role is more indirect in deforestation, spurring infrastructure development and enabling further agricultural expansion and colonization.