What Is a Technique That Police Use to Try and Minimize

What is a technique that police use to try and minimize faulty eyewitness identifications?

A) ensuring that the investigating detectives are not present to avoid inadvertent clues that may be picked up by the witness
B) allowing multiple witnesses to view suspect lineups at the same time so they can compare their recollections
C) focusing on in-person lineups as opposed to photo lineups
D) informing the witness that they may be subject to civil charges if they misidentify a suspect