Read the following passage: The vibrant coral reefs, often called the 'rainforests of the sea,' are home to a quarter of all marine species. They provide essential habitats, food sources, and protection for coastlines against storms. However, human activities such as overfishing, pollution, and climate change are causing widespread coral bleaching and degradation, threatening this crucial ecosystem. Protecting these reefs is vital not only for marine biodiversity but also for the livelihoods of millions of people worldwide.
✓ Correct Answer: Option B
Option B best summarizes the entire passage, encompassing the description of reefs, the threats they face from human activities, and the importance of their protection for both biodiversity and human livelihoods. The other options are too narrow.