After Inspecting a Patient's Left Lower Leg, the Nurse Leaves

After inspecting a patient's left lower leg, the nurse leaves the patient's room and asks the charge nurse to notify the patient's healthcare provider regarding a possible arterial thrombosis. What did the nurse assess to make this decision?

A) absent pedal pulses
B) skin cold to the touch
C) +4 edema on the ankle
D) foot unresponsive to sensation
E) line of demarcation across the foot