Which of the following describes the primary buffer coating?

The primary buffer coating refers to the layer that surrounds the core and cladding of a fiber optic cable. It plays a crucial role in ensuring the mechanical protection of the delicate fiber optics within. This coating is typically made of a polymer that provides a protective barrier, contributing to the fiber's durability while also allowing for some flexibility during installation and handling.

In the context of fiber optics, the primary buffer coating is essential for maintaining signal integrity and preventing damage caused by environmental factors or physical stress. Thus, identifying it as the layer that encapsulates the core and cladding highlights its primary function in the overall structure of fiber optic cables.