The correct option is (a).
Explanation
The Amazon Basin, home to the world's largest tropical rainforest, has undergone significant transformation due to human intervention and developmental activities. These changes have impacted accessibility, indigenous demographics, and the ecological balance of the region.
Statement-wise Analysis:
- Statement 1 is Correct: The construction of the Trans Amazon Highway in 1970 was a major developmental project intended to integrate the Amazon region with the rest of Brazil. It significantly altered the landscape by making previously remote and inaccessible parts of the rainforest reachable for settlement, logging, and other economic activities.
- Statement 2 is Incorrect: While developmental activities did force indigenous populations to displace and settle in new areas, they did not completely abandon their traditional practices. They generally continued to practice their distinctive way of farming (such as shifting cultivation or slash-and-burn agriculture) in these new locations, rather than abandoning them entirely.
- Statement 3 is Incorrect: Developmental activities, particularly deforestation and land clearing, have had a detrimental effect on the soil. In the rainforest, the topsoil is held together by the dense vegetation. When forests are cleared, the nutrient-rich topsoil is washed away by heavy tropical rains, often turning lush forests into barren landscapes, rather than preserving the soil.
Key Takeaway:
The opening of the Amazon Basin via the Trans Amazon Highway increased accessibility but led to the displacement of indigenous tribes and severe ecological degradation, including the loss of topsoil due to deforestation.