The answer is the second option. he added a new, costly missile system, which the soviet union needed to counter in the military buildup. I just took the quiz and got this question right.
He added a new military system--Reagan instituted the "Star Wars" program increasing spending on missile systems.
Reagan's increase in military spending caused the Soviet Union to reply as they had in the past in the arms race with the US. The USSR was hurting financially and struggled to keep up with the arms race. This would eventually hurt the USSR's resources lending to collapse.
