Which of the following examples demonstrates a security dilemma?
(a) turkey wants to join the european union even though the european union has criticized it for violations of human rights
(b) the united states and south korea run joint military exercises, and north korea responds by developing nuclear weapons
(c) the united states withdraws from the paris climate agreement despite the opposition of the ngo alliance
(d) turkey wants to assimilate the kurdish people by using military aggression.