Explanation: The correct answer is a. The procedure will assess the function of the client's immune system. A bone marrow aspiration is a diagnostic procedure that involves extracting a sample of bone marrow to evaluate the production and function of blood cells, including immune cells.

Incorrect choices:

b. A bone marrow aspiration does not involve removing lymph nodes. It is a procedure specifically focused on obtaining a bone marrow sample.

c. General anesthesia is not typically used for a bone marrow aspiration. Instead, local anesthesia is administered to numb the area around the bone marrow site.

d. A bone marrow aspiration is not a blood test to measure circulating antibodies. It is used to evaluate the bone marrow's cellular components, not circulating antibodies.