How can an event that blocks sunlight from reaching earth cause a mass extinction of consumers on Earth?

A. Decomposes depend on sunlight to recycle nutrients.
B. Consumers depend on producers to make food using sunlight.
C. Consumers depend on sunlight to make their own food.
D. Producers depend on sunlight only for light-dependent reactions.

It's B. Consumers depend of producers to make food using sunlight.