As a result of Mikhail Gorbachev coming to lead the USSR, A
the Soviet Union’s economy got worse and worse.

B
both the United States and Russia began to disarm.

C
anger between the United States and the USSR continued.

D
there were months and months of protest in the United States.

The soviet Union's economy got worse and worse

chronological thinking is an indispensable tool to structure a historical narrative and to give meaning to a sequence of events. the final section presents the results of a survey to test the chronological thinking of lower secondary school students carried out by the educational research institute.