What Does the Absence of a Tolerable Upper Intake Level

What does the absence of a tolerable upper intake level UL) for a specific nutrient indicate?

A) All food sources contain acceptable levels of the nutrient.
B) Insufficient data exist to establish a value for the nutrient.
C) Caution is only required when consuming supplements of the nutrient.
D) It is safe to consume in the nutrient in any amount.