Task: Instance Description Understanding (ontology: Sciences/Computer_Science)

Which of the following definitions best describes the instance 'nanomolar'?

A. A mass unit density which is equal to mass of an object in micrograms divided by the volume in liters.
B. A unit of molarity which is equal to one thousandth of one millionth of a molar or 10^[-9] M.
C. A unit of molarity which is equal to one thousandth of a molar or 10^[-3] M.
D. A volume per unit volume unit which is equal to one millionth of a liter of solute in one liter of solution.

Answer: A unit of molarity which is equal to one thousandth of one millionth of a molar or 10^[-9] M.