Final answer:
The correct nursing response is to unequivocally advise that the client should never smoke when oxygen is in use due to the extreme fire hazard and health risks associated with combining oxygen and lit cigarettes.
Step-by-step explanation:
The appropriate nursing response to a client who uses portable home oxygen and states that they still like to smoke cigarettes occasionally would be option b: "You should never smoke when oxygen is in use."
Oxygen greatly increases the risk of fire and explosion when exposed to a flame or spark, such as that from lighting a cigarette. Combining smoking with oxygen therapy is extremely dangerous and can cause serious harm or even death. Therefore, it is crucial to advise the patient about the severe risks of smoking while using oxygen equipment and to encourage complete cessation of smoking.