Final answer:
The priority action for a client with diabetes who feels dizzy, weak, and shaky is to check the blood glucose level to confirm if they are experiencing hypoglycemia, and then treat accordingly. Therefore, the correct option is D) Check the client's blood glucose level.
Step-by-step explanation:
When a client with diabetes mellitus reports feeling dizzy, weak, and shaky, these symptoms can indicate hypoglycemia, which is a potentially dangerous condition that occurs when blood glucose levels fall too low. The priority action by the nurse should be to immediately check the client's blood glucose level to ascertain whether these symptoms are due to hypoglycemia.
If the blood glucose level is confirmed to be low, the nurse should then quickly offer a fast-acting source of sugar such as 180 mL (6 oz) of orange juice to raise the blood glucose to a safe level. Documentation and education are important, but they are not the immediate priority in this scenario.
Therefore, the correct option is D) Check the client's blood glucose level.