Final answer:
The intake and output problem to report is when a client has not voided in eight hours, as it could indicate a urinary or renal issue needing medical attention.
Step-by-step explanation:
The intake and output problem that a nurse aide must report is C. the client has not voided in eight hours. This could indicate a potential urinary retention problem or renal issues which may require immediate medical attention. It is essential for a nurse aide to monitor and report any significant changes in a patient's urinary output as it can be a sign of serious health issues.
On the other hand, a client stating that they are not hungry (option A) is a less urgent concern unless it is a persistent issue leading to nutritional deficits. A client requesting a bedpan (option B) is a regular part of personal care assistance. An output of 600 cc in eight hours (option D), can be within the normal range depending on the fluid intake and the client's medical condition.