The correct answer is (c) 1992.
The 73rd and 74th Constitutional Amendments of 1992 reserved one-third of seats for women in Panchayati Raj bodies (panchayats and municipalities).
The 73rd Amendment (rural local bodies) and 74th Amendment (urban local bodies) were both passed in 1992. These mandated one-third reservation for women in Panchayati Raj institutions. Options (a), (b), and (d) are incorrect years. The textbook clearly states this provision under the chapter on Gender and Politics.