Step-by-step Solution:

The relationship between "FRUGAL" and "EXTRAVAGANT" is that they are antonyms. We need to find a pair with a similar antonymous relationship.

• A. Predecessor : Precursor – These are synonyms, not antonyms.
• B. Hermit : Philosopher – These are not antonyms; they describe different roles.
• C. Teacher : Philanthropist – These are not antonyms; they are different professions.
• D. Criticise : Advocate – These are antonyms, as criticize means to disapprove and advocate means to support.

Therefore, the correct pair is Criticise : Advocate.

Answer: D) Criticise : Advocate