It is an objective and standardised measure of an individual’s mental and/or behavioural characteristics.

Psychological Test

The correct answer is Option 4: Psychological Test

• Option 1: Interview: While useful, interviews are often subjective. The rapport between the person and the interviewer can change the outcome, and there isn't always a "standardized" score.

• Option 2: Case Study: This is an in-depth, qualitative look at a single individual or group. It is not standardized because every case is unique, making it impossible to apply a universal "measure" across different people.

• Option 3: Self-Report: This involves an individual providing their own account of their feelings or behaviors. While some self-reports are standardized (like certain personality inventories), the term "Self-Report" itself refers to a broad method of data collection that is prone to social desirability bias, making it less "objective" than a formal psychological test. 

NCERT: Psychological Test is an objective and standardised measure of an individual’s mental and/or behavioural characteristics. Objective tests have been developed to measure all the dimensions of psychological attributes (e.g., intelligence, aptitude, etc.) described above. These tests are widely used for the purposes of clinical diagnosis, guidance, personnel selection, placement, and training. Besides objective tests, psychologists have also developed certain projective tests, especially for the assessment of personality. "