Answer:
What city is marked by the letter A? Why is that city important?
The city marked by the letter A is Moscow. It is important because it is the current capital and largest city of the Russian federation, as it was the largest and capital of the Soviet Union.
Which region is marked by the letter B? Why is it controversial?
The region is Crimea, which consists of the peninsula of the same name, in between the black sea and Ukraine. It is controversial because this region as annexed by Russia several years ago, against the will of the Ukrainian government. This was justified on the basis that most of the Crimean population is of Russian origin, not of Ukrainian origin.
What body of water is indicated by the letter D? What happened there due to soviet rule?
The body of water is the Aral Sea. This inland sea, which used to be one of the largest in the world, has practically disappeared, and most of the blame falls on the Soviet Union lack of sound environmental policy. The lake was drained mainly due to over irrigation of the surrounding zones, and to desertification.