Identify the test conducted by the organisation at the time of selection.

A written test was conducted to judge the level of knowledge and proficiency of candidates.

Trade tests measure the existing skills of an individual.

They assess the level of knowledge and proficiency in a specific field.

Aptitude tests measure potential to acquire skills, not actual skills.

Hence, they are not applicable here.

Since the test evaluates actual knowledge and proficiency, it is a trade test.

Hence, the correct answer is:

Trade test.

Exact NCERT lines:

"Trade Test: These tests measure the existing skills of the individual. They measure the level of knowledge and proficiency in the area of professions or technical training. The difference between aptitude test and trade test is that the former measures the potential to acquire skills and the later the actual skills possessed."