The correct answer is: True.
The core region of an optical fiber is the inner part of the fiber that carries the light. The cladding is the outer part of the fiber that surrounds the core. The core and cladding are made of different materials with different refractive indices. The refractive index is a measure of how much light bends when it passes from one material to another. The refractive index of the core is higher than the refractive index of the cladding. This means that light will bend towards the core when it passes from the cladding to the core. This is called total internal reflection. Total internal reflection keeps the light inside the core of the fiber and prevents it from escaping.
Most of the optical power is carried out in the core region because the core has a higher refractive index than the cladding. This means that light is more likely to be reflected back into the core when it hits the boundary between the core and the cladding. As a result, most of the optical power is carried out in the core region.
The cladding does play a role in guiding the light, but its main purpose is to protect the core from damage. The cladding is also responsible for preventing light from escaping the fiber.