Final answer:
After a cerebral angiography, bleeding is the symptom that requires immediate action by the nurse, as it can lead to serious complications.
Step-by-step explanation:
The symptom displayed by the client that causes the nurse to act immediately after a cerebral angiography is A) Bleeding. Bleeding is a potential complication of vascular procedures like angiography and requires immediate attention to prevent further complications, such as a hematoma or severe blood loss. Immediate interventions might include applying pressure to the bleeding site, monitoring vital signs, and possibly administering blood transfusions if necessary. Other options such as increased temperature, severe headache, and the urge to void, though important to monitor, are not as immediately life-threatening as bleeding.