Answer:
The correct answer is D. Russia sharply increased its nuclear stockpiles from 1955 to 1985 and then the amount of stockpiles fell from 1985 to 2005.
Step-by-step explanation:
We can clearly see two trends in the development and stockpiling of nuclear weapons by the former Soviet Union, according to the graph presented. The first trend begins in 1955 and lasts until 1985, where significant growth is evident. Then, from 1985, the trend is contrary, decreasing rapidly until 2005, returning to the levels it had in 1975.