Which of the Following Defines a Subclinical Deficiency

Which of the following defines a subclinical deficiency?

A) a nutrient deficiency caused by inadequate dietary intake of a nutrient
B) a nutrient deficiency caused by something like a disease condition or drug reaction that reduces absorption, accelerates use, hastens excretion, or destroys the nutrient
C) a deficiency in the early stages, before the outward signs have appeared
D) a deficiency that exhibits conflicting outward signs, requiring laboratory diagnosis
E) an iron deficiency