विविध विषयांचे तज्ज्ञ म्हणून डॉ. बाबासाहेब आंबेडकरांनी पुढील ठिकाणी आपली साक्ष नोंदवली.
(a) सायमन कमिशन
(b) युनिव्हर्सिटी रिफॉर्म्स कमिटी
(c) रॉयल कमिशन ऑन इंडिअन करन्सी अॅन्ड फायनान्स
(d) साउथ बरो कमिटि

The correct answer is Option D (All (a), (b), (c) and (d)).

Key Points:
• Testimonies of Dr. B.R. Ambedkar before Various Commissions:
• Southborough Committee (1919): Dr. Ambedkar testified on franchise, demanding separate electorates and reserved representation for the Depressed Classes.
• Royal Commission on Indian Currency and Finance (Hilton Young Commission, 1925): Dr. Ambedkar appeared as an expert economist, presenting pathbreaking views on the exchange value of the rupee based on his treatise *The Problem of the Rupee*.
• Bombay University Reforms Committee (1924-25): Testified on reforming university governance and broadening access to higher education for marginalized communities.
• Simon Commission (1928): Submitted an extensive memorandum on behalf of the Bahishkrit Hitakarini Sabha and testified demanding universal adult suffrage and fundamental rights safeguards.
• Dr. Ambedkar testified before all four bodies (Option 4).
• Key Takeaway: Dr. Ambedkar testified before Southborough (1919), University Reforms (1924), Hilton Young (1925), and Simon Commission (1928).