Choose the correct thinkers/ideas from below:

A. Henri Fayol: Management Process School
B. Max Weber: Legal Irrational Authority
C. Mary Parker Follett: Idea of Constructive Conflict
D. Elton Mayo: The Great Illumination Experiment
E. Chester Barnard: Spiritual Father of Social System School

Choose the correct answer from the options given below:

Correct option is C

Lets evaluate each statements :

A. Henri Fayol: Management Process School - Correct. Henri Fayol is a key figure in the Management Process School of thought. He developed the concept of management functions (planning, organizing, leading, and controlling) and is considered one of the early contributors to modern management theory.

B. Max Weber: Legal Irrational Authority - Incorrect. Max Weber's concept is "legal-rational authority", not "legal irrational authority." This concept refers to authority based on established rules and laws, typically seen in bureaucratic organizations.

C. Mary Parker Follett: Idea of Constructive Conflict - Correct. Mary Parker Follett emphasized the Idea of Constructive Conflict, where conflicts should be seen as opportunities for collaboration and integration, not competition.

D. Elton Mayo: The Great Illumination Experiment - Correct. Elton Mayo conducted the Hawthorne Studies, also known as the Great Illumination Experiment, which highlighted the role of social and psychological factors in worker productivity.

E. Chester Barnard: Spiritual Father of Social System School - Correct. Chester Barnard is considered the Spiritual Father of the Social System School, where he focused on organizations as cooperative systems and emphasized the importance of communication and cooperation.

Hence,  Option (c)  A,C,D,E is the correct choice.