Analyzing the relationship in each pair:
Option 1: Beautician : Parlour
A beautician works at a parlour. This shows a person-to-workplace relationship.
Option 2: Chemist : Medicine
A chemist deals with or dispenses medicine. This shows a person-to-product relationship, not a person-to-workplace relationship.
Option 3: Lawyer : Court
A lawyer works at a court. This shows a person-to-workplace relationship.
Option 4: Engineer : Site
An engineer works at a site. This shows a person-to-workplace relationship.
Options 1, 3, and 4 all follow the pattern: Professional : Workplace
Option 2 follows the pattern: Professional : Product/Material
Therefore, Option 2 (Chemist : Medicine) is the odd pair as it does not represent a person-to-workplace relationship like the other three pairs.