I think the answer to this is D.
From the description of the food that the doctor is advising Natalia to start consuming, it is clear that she is suffering from (C) Vitamin D deficiency.
Someone with a vitamin D deficiency would be at risk of rickets, an illness where someone will have skeletal deformities due to soft bones. Increased risk of death due to cardiovascular disease and cancer is also associated with someone who has a vitamin D deficiency.
