The correct answer is A) Visible and audible alarms indicating excessive superheat shall be provided. This is the correct answer because the Coast Guard regulations require that for boiler installations where the superheater outlet temperature exceeds 850°F, visible and audible alarms must be provided to indicate excessive superheat. This is a safety measure to alert the operator of potentially dangerous conditions in the superheater. The other answer choices are incorrect because they do not accurately represent the Coast Guard regulations for this specific type of boiler installation. Answers B, C, and D describe different requirements that are not applicable in this case.