What is a very large mountain range running along the center of the ocean floor called?

A very large mountain range that runs along the center of the ocean floor is known as an ocean ridge. These underwater mountain ranges are formed by tectonic plates that are pulling apart, allowing magma to rise from below the Earth's crust, solidifying and creating new oceanic crust. The Mid-Atlantic Ridge is one of the most well-known examples of an ocean ridge, where the Eurasian and North American plates are diverging.

This geological feature is significant because it plays a crucial role in the process of seafloor spreading, which is a fundamental aspect of plate tectonics. The formation and movement of ocean ridges contribute to the dynamic nature of the Earth's geology, influencing ocean currents and ecosystem habitats.

Other choices do not accurately describe this phenomenon. A coral reef refers to a structure made from coral polyps, typically found in shallow, warm ocean waters, while ocean peaks could refer to any uplift on the seafloor, but do not specifically denote the extensive ridges. Glaciation pertains to the process of ice formation and movement, which is unrelated to oceanic geological formations. Thus, ocean ridge is the term that precisely describes the extensive mountain ranges found on the ocean floor.