Q. A 72 year-old female presents to clinic for bilateral feet pain. She characterizes the pain as a burning sensation located that the soles of her feet. She is unable to stand on her feet for long periods of time due to the pain. She has a medical history of alcoholic cirrhosis requiring liver transplantation maintained on tacrolimus. On neurological exam, she has reduced sensation to pinprick and temperature. Proprioception and vibration are intact. She has 5/5 strength in her upper and lower extremities throughout. Her reflexes are reduced in all her extremities. Her clinical presentation is concerning for a peripheral neuropathy. Which of the following spinal tracts is most likely affected in this patient?