A 55-year-old patient with extensive cardiac history has been in the ICU for more than 6 weeks because of multiple infections, sepsis, and severe heart failure. He also has an external cardiac pacemaker. The intensive care team has noticed that within the last few weeks he was not able to move his limbs and is concerned about a critical illness disease. An electrodiagnostic study is requested. Just before starting the study, the external pacemaker wires are noted. Which of the following options is the best course to take?
A. Perform nerve conduction studies in the lower limbs only
B. Perform nerve conduction studies in the upper limbs only
C. Perform needle EMG only
D. Perform repetitive stimulation of the ulnar nerve only