Ground-fault protection of equipment is required for which of the following systems?
A. 208Y/120 volt, 3-phase, 4-wire with an 800-ampere main breaker
B. 208Y/120-volt, 3-phase, 4-wire with a 1200-ampere main breaker
C. 480Y/277-volt, 3-phase, 4-wire with an 800-ampere main breaker
D. 480Y/277-volt, 3-phase, 4-wire with a 1200-ampere main breaker
D. 480Y/277-volt, 3-phase, 4-wire with a 1200-ampere main breaker
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