The sino-soviet split was followed by an economic agreement between

The answer is d) The US and USSR

The Sino-Soviet Split was a pivotal historical event which took place over the course of a few years between 1956-1966.

The post-Stalinist Soviet Union diverged from China's own communist, Marxist and Leninist views.

The split was followed by an economic agreement between the United States and the USSR. 

However, the effects of this split were felt far and wide all over the world and for many years to come.

In the next decade, China took steps to officially open to the United States with Nixon's state visit to the country.

Both countries had to aprove annexation.