"Which statement best describes the ocean floor?"
a. It is mostly flat, with little distinguishing features.
b. It is mostly covered with undersea mountain ranges.
c. It is varied and includes mostly undersea volcanoes and seamounts.
d. It is varied and includes features such as submarine canyons, atolls, and mid-ocean ridges.

d. It is varied and includes features such as submarine canyons, atolls, and mid-ocean ridges.

Explanation: The floor of the ocean is widely varying, similar to the different types of landforms we see on land. It is made up of seamounts, mountain like formations, trenches and has thriving land forms close to the shore. However, this reduces the deeper the sea floor as sunlight cannot penetrate as easily. Due to the absence of sunlight, plants are fewer and this in turn affects the population of animals that feed on them.