The exact extract asks for the cutoff time of Huawei's industry-first DC-to-ground protection solution. The correct answer is B. 10 ms. DC-to-ground faults are serious in PV systems because they can create leakage current, insulation failure, electric-shock hazards, fire risk, and equipment damage. A fast protection mechanism is valuable because it disconnects the fault before the fault energy increases and before the problem spreads to other parts of the PV system. Huawei positions advanced DC-side protection as part of its active safety architecture for C&I and large-scale PV systems. The key differentiator in this question is speed: the fault must be detected and cut off rapidly. Among the listed values, 10 ms is the selected and correct Huawei training value. The longer values of 15 ms, 30 ms, and 60 ms do not match the stated industry-first fast DC-to-ground cutoff capability. Reference: Huawei HCSA-Sales-Smart PV V2.0 C&I Solution active safety training extract.