Which of the following correctly describes the nature of discrete quantitative variables?

A.They are characteristics possessed by persons or objects, called elementary units, in which we are interested.B.They can assume values only at specific points on a scale of values, with inevitable gaps between successive observationsC.When dealing with such variables, we can count all possible observations and, with some exceptions, that count leads to a finite result.

D.Is correctly described by "they are characteristics possessed by persons or objects, called elementary units, in which we are interested" and "when dealing with such variables, we can count all possible observations and, with some exceptions, that count leads to a finite result."E.All of these.