Correct Answer: Iran

Solution : The correct answer is Iran.

NSG or Nuclear Suppliers Group is an International Organisation which aims to curb the proliferation of nuclear weapons. It was formed in 1974 and presently it has 48 member countries. France, United States of America, and Russia all the three countries are members of it but Iran is not its member. To become a member of NSG a country has to be a signatory of 1968 convention on non proliferation of nuclear weapons also known as non proliferation treaty (NPT).