Final answer:
A non-rebreather mask should be selected to deliver oxygen to the patient.
Step-by-step explanation:
The device that should be selected to deliver oxygen to the five-year-old patient with asthma symptoms is a non-rebreather mask. A non-rebreather mask is a device that fits over the patient's nose and mouth, and it has a reservoir bag that is filled with oxygen. It is designed to deliver high-flow oxygen and prevent the patient from re-breathing exhaled carbon dioxide. This mask is particularly beneficial in cases where the patient's oxygen saturation is dropping, as indicated by the pulse oximeter reading in this scenario.