Modern corals are restricted to growing in warm, clear, well-lit, shallow water. over the last two million years, coral reefs have undergone periods of great growth as well as mass extinctions. all but one catastrophic event has contributed to the changes in reefs over the years. that is a) meteor impacts. b) global ice ages. c) destruction of the rainforest. d) the rise and fall of sea level.

The answer is C, destruction of the rainforest.

Option (C)

Explanation:

The corals are directly affected due to the destruction of the rainforest.

Over the last few million years, the corals have grown as well as destroyed. They also resulted in the damages and occurrence of various changes in the corals.

When the forest areas were destroyed and lost, the soil particles are washed away into the rivers and streams, carrying all its essential minerals. These minerals are then transported to the seas and oceans. This presence of minerals in excessive amount causes negative effect on the growth of corals. In addition to this, when these large amount of eroded materials are added to the ocean, it forms a cloud, as a result of which the sunlight cannot penetrate into the zone where corals are abundantly present.

Thus, the destruction of rainforest caused various changes in the corals reefs.

Hence, the correct answer is option (C).