Answer:a. standardization
Explanation:
Standardization means creating uniformity in scoring and administration of the test. In order to make effective comparison in scores from different people testing conditions must be kept uniform.
Standardization of a test is tested on a representative sample for which it is designed , the representative sample is used to determine the norms.
Norms for personality test are the same for aptitude test they have to correspond to the performance of the participants.