(G.K. Group A)-2022 The question asks to identify a treaty signed on August 31, 1989, from the given options. Upon historical review of the signing dates of the mentioned treaties, none of them precisely match the date provided for their initial signing or entry into force. This indicates a potential error in the question or the options. If the provided correct answer is C (Nuclear Non-Proliferation Treaty), then there must be a specific, albeit perhaps obscure, event related to this treaty that occurred on August 31, 1989, which is not widely documented as a primary treaty signing date.