Passage: Read the given passage and answer the questions that follow. Migration is a key aspect of ecological balance, showcasing nature’s precision and perseverance. Species such as the monarch butterfly, which flies from North America to Mexico, and the Arctic tern, which undertakes a nearly 44,000-mile journey from the Arctic to Antarctica, demonstrate extraordinary navigational abilities. These feats often rely on mechanisms like olfactory signals, geomagnetic sensitivity, and celestial navigation. Yet, how these complex processes are innately understood by animals—like birds that migrate without guidance— remains largely mysterious, hinting at a blend of instinct, environmental cues, and genetic programming. However, the continuity of migration is under threat due to human-induced disruptions such as habitat fragmentation, pollution, and climate change. These issues endanger species, reduce biodiversity, and destabilize ecosystems. In response, efforts like international conservation agreements, habitat restoration, and advanced tracking technologies aim to protect migratory routes. Success, however, requires global cooperation and prioritization of ecological stability over immediate economic gains. Beyond its biological importance, migration symbolizes resilience, adaptability, and interconnectedness—reminding us of nature’s persistent drive to endure despite adversity. Question: Which of the following can be inferred from the passage?

1. Economic development always supports the preservation of migratory routes.
2. Animals migrate only for the sake of scientific study.
3. Migration is fully understood and easily explained by modern science.
4. Human activities pose a significant threat to the natural process of migration.