Question 5 of 22 Scientists report (1) that creatures living in the deep sea are in danger of starving to death. Millions of undiscovered species live, in the deep sea. Creatures in the seabed are suffering from growing food shortages. Which may be a result of rising sea temperatures. Scientists believe that some species will die out, those that can survive on a low food supply will continue living. Not much is known about the creatures that live in the deep sea, not much is known about the changes in their diets. Scientists estimate that up to 10 million species live in the depths of the sea. Most animals of the deep rely on food chains that begin. In the lighted realms of the sea. Microscopic plants called phytoplankton. Capture the sun and start the food cycle. (2) Wherever there are animal droppings, there is a constant rain of organic matter (3) that feeds the bottom dwellers. It is uncertain what will happen to the rest of the food chain (4) when these bottom dwellers become extinct.
Read the paragraph.
Which underlined portion contains a noun clause?
A. 1
B. 2
C. 3
D. 4