A gangster was brought to the ED with a penetrating neck injury after a fight. Which of the following is used to define 'Penetrating Neck Injury'?

Penetrating injuries of the anterior neck are defined as the injuries that violate the platysma muscle. They are potentially life-threatening because of the density of critical structures in this region. CT scanning of the neck and chest determines the injury track, and fuher studies are performed based on proximity to major structures. Also know: For the purpose of evaluating penetrating injuries, the neck is divided into three zones. Zone I is up to the level of the cricoid and is also known as the thoracic outlet. Zone II is located between the cricoid cailage and the angle of the mandible. Zone III is above the angle of the mandible. Ref: Cothren C., Biffl W.L., Moore E.E. (2010). Chapter 7. Trauma. In F.C. Brunicardi, D.K. Andersen, T.R. Billiar, D.L. Dunn, J.G. Hunter, J.B. Matthews, R.E. Pollock (Eds), Schwaz's Principles of Surgery, 9e.