Clarisa has been a vegan for 10 years. Therefore, she avoids eating any foods that are from animal sources, including milk and eggs. She also doesn't take any vitamin supplements. Lately, she hasn't been feeling well. The muscles of her legs ache; she's having trouble walking and keeping her balance; and the top of her tongue is smooth and shiny. Today, her fingers began to feel numb, so she's made an appointment to see a physician. Based on this information, Clarisa probably has
a) Ariboflavinosis
b) Scurvy
c) Vitamin B6 toxicity
d) Vitamin B12 deficiency