Many big organizations maintain a close liaison with the universities, vocational schools and management institutes to recruit qualified personnel for various jobs. This process of recruitment is known as:

Campus recruitment

The correct answer is option 4- Campus Recruitment.

Campus Recruitment: Colleges and institutes of management and technology have become a popular source of recruitment for technical, professional and managerial jobs. Many big organisations maintain a close liaison with the universities, vocational schools and management institutes to recruit qualified personnel for various jobs.

Direct Recruitment- Under the direct recruitment, a notice is placed on the notice-board of the enterprise specifying the details of the jobs available. Jobseekers assemble outside the premises of the organisation on the specified date and selection is done on the spot. The practice of direct recruitment is followed usually for casual vacancies of unskilled or semi-skilled jobs. 

Labour Contractors: Labour contractors maintain close contacts with labourers and they can provide the required number of unskilled workers at short notice. Workers are recruited through labour contractors who are themselves employees of the organisation.

Placement Agencies and Management Consultants: In technical and professional areas, private agencies and professional bodies appear to be doing substantive work. Placement agencies provide a nationwide service in matching personnel demand and supply.