It is a long time for a large mount of big corporations or international companies to pay much attention to an ever-important subject -- Industrial Psychology. For studying and using the subject, they can produce more profits than ever before. So, what is its definition It is an application of various psychological techniques to the selection and training of industrial workers and to the promotion of efficient working conditions and techniques, as well as individual job satisfaction. This field of applied psychology first became prominent during World War II, when it became necessary to recruit and train the large number of new workers who were needed to meet the expanding demands of industry. The selection of workers for particular jobs is essentially a problem of discovering the special intelligence and personality characteristics needed for the job and of devising tests to determine whether candidates have such intelligence and characteristcs. The development of tests of this kind has long been a field of psychological research. Once the worker is on the job and has been trained, the fundamental aim of the industrial psychologist is to find ways in which a particular job can best be accomplished with a minimum of effort and a maximum of individual satisfaction. The psychologist’s function, therefore, differs born that of the so-called efficiency expert, who places primary emphasis on increased production. Psychological techniques used to lessen the effort involved in a given job include a detailed study of the motions required to do the job, the equipment used, and the conditions under which the job is performed. These conditions include ventilation, heating, lighting, noise, and anything else affecting the comfort or morale of the worker. After making such a study, the industrial psychologist often determines that the job in question may be accomplished with less effort by changing the routine motions of the work itself, changing or moving the tools, improving the working conditions, or a combination of several of these methods. Industrial psychologists have also studied the effects of fatigue on workers to determine the length of working time that yields the greatest productivity. In some cases such studies have proven that total production on particular jobs could be increased by reducing the number of working hours or by increasing the number of rest periods, or "breaks", during the day. Industrial psychologists may also suggest less direct requirements for general improvement of job performance, such as establishing a better line of communication between employees and management. The other aim of psychological research is to ______.

A. find ways in which a particular job can best be accomplished with a maximum of effort and a minimum of individual satisfaction
B. place primary emphasis on increased salaries
C. lessen the effort involved in a given job include a detailed study of the motions
D. promote efficient working conditions and techniques, as well as individual job satisfaction