(B) Incorrect.

This patient does have a proximal DVT. The anatomic differentiation between proximal and distal clot is the popliteal vein. Involvement of the popliteal or more proximal vessels is thought to constitute a significantly greater risk of embolization than clots limited to the calf veins. In fact, some authorities question whether anticoagulation therapy is even necessary for patients with calf-only clots if close follow-up can be maintained. That this patient has proximal clot mandates therapy.