The correct options are
B NATO was formed in 1948 as a defence alliance.
D NATO was officially disbanded after the Warsaw pact was dissolved in 1991.
North Atlantic Treaty Organisation (NATO) was formed in 1949. This organisation was formed to protect Western Europe from possible threats of the Soviet Union. The US-led military alliance stood by Western Europe up till the end of the cold war. NATO has 30 members at present. There were 12 founding members in 1949. They are: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Portugal, United Kingdom and USA.