Read this passage from the National Oceanic and Atmospheric Administration, or NOAA. What should you NOT infer from these sentences?

If a fringing reef forms around a volcanic island that subsides completely below sea level while the coral continues to grow upward, an atoll forms. Atolls are usually circular or oval, with a central lagoon.

-Lagoons surround fringing reefs.

-Atolls have submerged volcanic islands in their midst.

-Some atolls are not circular or oval.

-Some fringing reefs create atolls.

We cannot infer Option C: Some atolls are not circular or oval ...

Explanation:

There are three coral reef types: fringing, barrier and atoll. These three share similar bio-geographic profiles.

Fringing reefs grow around islands and continents. Barrier reefs are also formed along the coastline but they are separated by deeper lagoons. Atolls are formed when island that surrounds fringing reef sinks into the sea. Then, the sea level rises. Fringing reef keeps growing and form circles with lagoons inside, creating an atoll. They are usually in the middle of the sea.

From the given excerpt, what cannot be inferred is Option C.