Final answer:
The nurse should plan to see the client with pneumonia first due to the seriousness of the condition and the presence of underlying health issues.
Step-by-step explanation:
To determine which client the nurse should plan to see first, we need to prioritize based on the urgency of each situation. Given the information provided, the client who requires immediate attention is the one with a fever and symptoms of pneumonia. Pneumonia can be a serious condition, especially for individuals with underlying health issues like asthma and diabetes. The nurse should prioritize assessing and providing care to this client to prevent any complications.