A nurse manager participates in a quality-improvement committee seeking to reduce the risk of sentinel events in a healthcare facility. When reviewing recently submitted incident reports, which of the following incidents should the nurse identify as a sentinel event?

The wrong operation was performed on a patient.

A client received an incorrect dose of medication, but it did not result in injury.

A patient complains that a nurse was rude and abrasive.

A nurse withholds a medication upon suspecting that the patient may be allergic to the drug.