Final answer:
The safety valves in a boiler should be connected independently of any steam connection if required by an inspector.
Step-by-step explanation:
The subject of this question is Engineering. Specifically, it pertains to the safety valves used in boilers.
The correct answer to the question is option d) if required by inspector. The safety valve or valves should be connected to the boiler independent of any steam connection if it is deemed necessary by the inspector.
For example, if the inspector determines that the safety valve is not functioning properly or there is a risk of overpressure in the boiler, they may require the safety valve to be connected.