Which of the following best summarizes the main idea of the passage below? "For centuries, the monarch butterfly has undertaken an extraordinary migration, traveling thousands of miles from Canada and the U.S. to overwintering sites in Mexico and California. This journey is one of the most remarkable feats in the insect world, but recent declines in population due to habitat loss and climate change threaten its future."
✓ Correct Answer: Option B
Option B accurately captures both the remarkable migration and the critical threat it faces, which is the central point of the passage.