A 75-year-old patient has a sore tongue with tingling and numbness of the hands and feet. She has headaches and is fatigued. Following diagnostic workup, the doctor orders monthly injections of vitamin BIX This patient most likely has which of the following conditions?
A. aplastic anemia
C. pernicious anemia
B. autoimmune hemolytic anemia
D. sickle cell anemia
Answer: C