What is As described by Katz, the premolar relationship of this patient can be classified into: and explain in detail?
Morton Katz (1992) shifted the focus from the molars, canines and incisors to the region of premolars for the purpose of classifying malocclusion. He highlighted the shortcomings of Angle’s molar based system of classification. He proposed a modification to Angle’s system of classification based on premolar occlusion, which used an objective approach of measuring the anteroposterior discrepancy with calipers.
Class I – Most anterior upper first premolar fits into the embrasure created by the distal contact of the most anterior lower premolar.
Class II - Most anterior upper premolar occluding mesial to the embrasure created by the distal contact of the most anterior lower premolar. 
Class III - Most anterior upper premolar occluding distal to the embrasure created by the distal contact of the most anterior lower premolar.
 
Ref: Katz MI. Angle classification revisited 2: a modified Angle classification. Am J Orthod Dentofacial Orthop. 1992;102(3):277–284: PubMed PMID: 1510054. 
Image : Tehranchi A, Behnia H, Younessian F, Hadadpour S. Advances in Management of Class II Malocclusions. A Textbook of Advanced Oral and Maxillofacial Surgery. 2016 Aug 31;3:3455.