How did reagan's cold war strategy change after gorbachev took power?
reagan began to focus more on military buildup.
reagan agreed to ban some nuclear missiles.
reagan recommended a return to the détente policy.
reagan took a more aggressive approach to the cold war.

The nuclear arms limitation (SALT I and SALT II) came into affect in the early and late 70s. That would make that option not possible as Reagan was elected in 1980 and Gorbachev came into power in 1985. You could argue between the detente and aggressive choices. Reagan funded anti-communist groups across the world that could be considered aggressive but not that aggressive. Later on Reagan started to consider the idea of detente and I believe that would make that the best option.

there are two main types of historical sources: primary sources and secondary sources. a primary source is something that originates from the past. it can be a chronicle, a piece of pottery, or even a piece of glacial ice that gives us climate data about the levels of atmospheric carbon one thousand years ago.