Depends on the test to be honest.Also the job you are working for or want.
        
             
        
        
        
 Answer:
 d. Soviet Union dissolved, ending the Cold War
Explanation:
The head of the USSR at the moment Mikael Gorbachov decided that the time had come for a series of Reforms and major changes in the structures of the economic and political bodies.
 By approaching the West he formalized the dissolution of the Soviet Union. The Russian and Americans began to seek cooperation in a series of topics that would pose a new agenda. 
No longer could Cold war politics prevail.
Especially, the threat of terrorism that both sides suffered, made strong efforts into defining a new policy sometimes reflected in bilateral agreements. 
With the collapse of the Soviet Union started in the late 1980 countries in the periphery of Russia began to approach US bilateral cooperation as well.
 The resulting 15 independent states after 1991 meant also an effort to demilitarize the region. The case was most clear in Ukraine that gave up all the nuclear warheads to Russia. 
 
        
             
        
        
        
Answer:
As part of the Compromise of 1850, the Fugitive Slave Act was amended and the slave trade in Washington, D.C., was abolished. Furthermore, California entered the Union as a free state and a territorial government was created in Utah.
Explanation:
please mark brainlest
 
        
             
        
        
        
Answer:
Biological
Explanation:
Memory allows for the storing and retrieval of information after seconds to years and is important for everyday life.
Progress in understanding memory function can be supported by first diagnosis of dementia, mild cognitive impairment, natural ageing, schizophrenia, and stroke. 
Understanding the biological basis of learning, memory, behaviour, perception and consciousness has been described as the biological sciences greatest challenge.