Final answer:
A biphasic lower extremity Doppler tracing is generally considered abnormal since normal flow is typically triphasic. However, its interpretation may vary based on clinical context and patient history.
Step-by-step explanation:
The question relates to the interpretation of a Doppler ultrasound test result for lower extremity arteries. A biphasic lower extremity Doppler tracing indicates that there are two distinct phases in the blood flow pattern. This can be considered abnormal as normal blood flow in the lower extremities is typically triphasic, signifying three distinct phases of blood flow velocity (forward flow during systole, brief reversal of flow or pause, and then forward flow during diastole). However, the interpretation of biphasic results can vary based on the clinical context, as it may be normal in certain scenarios, such as when found in patients post-exercise or in the presence of a stiff, non-compliant vessel wall due to atherosclerosis or diabetes. Therefore, the answer here would be (b) Abnormal, but with nuances depending on clinical circumstances.