Final answer:
The finding that warrants an incident report when a nurse administers ceftazidime to a client with a severe penicillin allergy is difficulty breathing.
Step-by-step explanation:
If a nurse administers ceftazidime to a client with a severe penicillin allergy, the finding that warrants an incident report is c. Difficulty breathing. Difficulty breathing is a symptom of an allergic reaction known as anaphylaxis, which is a severe and potentially life-threatening condition. It is important to document and report this finding to ensure the client receives immediate medical attention.