Final answer:
The assessment data that indicates a worsening of the patient's condition is the presence of fixed unresponsive pupils.
Step-by-step explanation:
The nurse should assess for presence of a fixed and unresponsive pupil, which indicates a worsening of the patient's condition. This is a concerning sign as it may indicate brainstem dysfunction or herniation, leading to increased intracranial pressure.
For example, if the nurse shines light in both eyes and observes that the pupils do not constrict at all, this suggests that the patient's condition is worsening. In contrast, if the pupils constrict briskly in response to light in both eyes, this would not indicate a worsening condition.
Therefore, option A, presence of fixed unresponsive pupils, would indicate a worsening of the patient's condition.