The correct answer is A) 5" Hg. The low-pressure cutout switch is designed to protect the refrigeration system from operating at too low of a pressure, which can damage the compressor. The cut-in pressure is the pressure at which the switch will allow the system to restart, and the cut-out pressure is the pressure at which the switch will shut the system down. Given that the cut-in pressure is 5 psig and the differential is 7.5 psig, the cut-out pressure can be calculated as 5 psig - 7.5 psig = -2.5 psig. This value is equivalent to approximately 5" Hg, which is the correct answer. The other options are incorrect because: B) 0 psig is the cut-in pressure, not the cut-out pressure. C) 2.5 psig is the cut-in pressure, not the cut-out pressure. D) 12.5 psig is the sum of the cut-in pressure and the differential, not the cut-out pressure.