From the following options presented in the problem, the only global city in the region of Russia and its neighboring countries would be A. Moscow.
Of the options presented, between Moscow, Kiev, St. Petersburg, and Tashkent, the only global city would be Moscow. Kiev and Tashkent aren't located in Russia. This leaves Moscow and St. Petersburg. Although some would argue that St. Petersburg would be the answer, it is a fact that St. Petersburg is yet to be called as a global city. Moscow, on the other hand, is already declared one though its activities as one is limited. Both are solely affected as to Russia's approach in the overall development of the country and is yet to show progress.