Roland Is a Police Officer in Pursuit of a Fleeing

Roland is a police officer in pursuit of a fleeing rape suspect. The chase is on foot, and Roland is a much faster runner than his partner. He catches the suspect out of sight of his partner. When his partner, Ted, arrives on the scene, he observes Roland striking the suspect, despite the fact that the suspect is already in handcuffs. When the case comes to trial, Ted maintains his story on the witness stand. This is known informally as:

A) a blue screen.
B) discretion under oath.
C) "dilemma of duty."
D) "testilying."