Final answer:
An incident report should be completed by the nurse in the situation where a client was administered one-half of the prescribed dose of medication.
Step-by-step explanation:
An incident report should be completed by the nurse in the following situation: c) A client was administered one-half of the prescribed dose of medication. This is considered a medication error, and it is important for it to be documented for quality improvement and to identify any patterns or trends in medication errors.
In the other situations:
a) A client refuses electroconvulsive therapy after signing the consent form - Although the client's refusal needs to be documented, it does not require an incident report.
b) A client who was voluntarily admitted left the unit against medical advice - This needs to be documented, but it does not require an incident report.
d) A client's family member expresses dissatisfaction with the care provided - This is not an incident that requires an incident report but should be addressed through appropriate channels for patient satisfaction feedback.