Emily is developing a computer model of protist populations in certain areas of the ocean, and how they help maintain homeostasis in ecosystems. Photosynthetic protists play essential roles in the environment, especially in oceans and lakes. If a hypothetical catastrophic event drastically reduced the population of zooxanthellae, a photosynthetic protist with a specific habitat, which statement describes the most likely result?

A. Almost half of the photosynthesis occurring on Earth would be in jeopardy, and species from shrimp to whales would lose an important food source.
B. Kelp forests would experience a drastic reduction in size, eliminating shelter for many marine species and a food source for sea urchins.
C. The health of coral reefs would suffer and reef populations would decrease in size and stability.
D. The equilibrium of the ecosystem surrounding hydrothermal vents would be upset, leading to loss of diversification.