Solution:Robert Dubin as the harbinger of the systems approach, Robert Cox with the Peasant-Lord model, Kenneth Walker with the multidimensional interactive model, and John T. Dunlop with the expansion from collective bargaining to full industrial relations.A-IV (Robert Dubin → Harbinger of Systems Approach): Robert Dubin, through his early work in Industrial Sociology, laid the conceptual foundation for viewing industrial relations as a system of interactions, long before the formal systems model was articulated. He emphasised that workplace behaviour, organisational goals, and external influences must be understood as interconnected elements. This makes him a pioneering figure or "harbinger" of the systems viewpoint.
B-III (Robert Cox → The Peasant-Lord System): Robert Cox identified different historical stages of industrial relations in India. One key stage was the Peasant-Lord System, representing a highly unequal relationship where labour was weak and dependent, while management exercised dominance-much like the historical peasant-landlord hierarchy.
C-I (Kenneth Walker → Multi-Dimensional, Inter-Active Model of Industrial Relations): Walker highlighted that industrial relations is not merely about rules and dispute resolution; it is a multidimensional, interactive framework shaped by economic, technological, social and political forces. His approach underscored the dynamic interplay among these factors, giving rise to a multidimensional IR model.
D-II (John T. Dunlop → Collective Bargaining to Full Spectrum of Modern Industrial Relations): Dunlop's landmark work Industrial Relations Systems broadened the understanding of IR from traditional collective bargaining to an integrated system involving actors (employers, employees, government), contexts, and rule-making processes. His model demonstrated how IR encompasses the entire spectrum of interactions and regulatory mechanisms shaping the workplace.