The correct option is that all three statements are not correct.

Statement I is incorrect because Panchayats at the intermediate level do not exist in all states; they are present only in certain states as per the provisions of the Panchayati Raj system. Statement II is incorrect as the minimum age to be a member of the intermediate level Panchayat is 21 years, not 30 years. Finally, Statement III is misleading; while a State Finance Commission does review the financial position of the Panchayats, it is not specifically the Chief Minister who constitutes this commission; it is established under Article 243-I of the Constitution. This understanding is crucial as it reflects the specific structural and operational details of the Panchayati Raj system as outlined in constitutional provisions and relevant governance frameworks, which are key topics in UPSC preparations.