A 63-year-old female presents to the hospital's dialysis clinic for dialysis. During a routine workup of the patient while receiving dialysis, the charge nurse notices that the woman has no soft tissue associated with her big toe. Palpation of the skin reveals that the skin covers bone and no other tissues. When the nurse asks the patient if she has noticed anything going on with her, the patient replies, "I haven't felt my feet in years." The patient is also obese and is being treated for hypertension, hyperlipidemia, and hyperglycemia. Diabetes over time may lead to neuropathy, and abnormal or poor sensations.
Why was the patient unable to feel her feet?
a Damage caused by hypertension
b Genetic mutation affecting her ability to feel pain
c Diabetic neuropathy had destroyed the nerves over time
d Advanced age