The Critical Feature of a Police Line-Up Is

The critical feature of a police line-up is:

A) the absolute number of participants from which the witness may identify the culprit
B) the nature of the crime for which the culprit is charged
C) the type of description given by the eyewitness prior to the line-up
D) the functional number of participants from which the witness may identify the culprit
E) whether or not the witness has an experience with other line-ups