Let us analyze each protection scheme:
* Type A Protection :
* Protects only the trunk fiber (between the OLT and the splitter).
* Does not protect branch fibers.
* Type B Single-Homing Protection :
* Protects the trunk fiber but does not extend protection to branch fibers.
* Type B Dual-Homing Protection :
* Similar to Type B single-homing but uses two OLTs for redundancy. Still does not protect branch fibers.
* Type C Protection :
* Provides end-to-end protection , covering both the trunk and branch fibers.
* Uses redundant fibers and splitters to ensure continuity in case of failures in either the trunk or branch fibers.
Thus, the correct answer is D , as Type C protection is the only scheme that protects branch fibers.
References:
* HCIA Huawei ACCESS Official Documentation , Chapter: GPON Protection Mechanisms.
* GPON Redundancy and Protection Schemes by Huawei.