It would be "Siberia" that lay farthest from the center of power in St. Petersburg, since Siberia represents a vast amount of territory that stretches all the way to the Pacific Ocean.
The Russian territorial possession that lay farthest from St. Petersburg is Alaska, as it is located across the Bering Strait and is significantly more distant than the other options presented. This makes it the most isolated territory in relation to the capital. Therefore, the answer is A. Alaska.
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