The correct answer is A. 1999.
In 1999, 19 NATO members and 11 ‘Partners for Peace’ joined hands for a peace plan for the Kosovo Crisis. The plan was to end the violence between the Serbian government and the Kosovo Albanians, and to establish an independent Kosovo. The plan was successful, and Kosovo declared independence in 2008.
Option B, 1989, is incorrect because the Kosovo Crisis did not begin until 1998. Option C, 1979, is incorrect because the Kosovo Crisis was not a major issue at that time. Option D, 1969, is incorrect because the Kosovo Crisis did not even exist at that time.