Final answer:
The countries of Poland, Latvia, Lithuania, and Estonia gained independence in 1917 after a series of revolutions broke out in Russia.
Step-by-step explanation:
The subject of this question is History.
In 1917, a series of revolutions broke out in Russia. These revolutions led to the gain of independence for the countries of Poland, Latvia, Lithuania, and Estonia.
Therefore, the correct answer is D Russia.
Learn more about Independence of Poland, Latvia, Lithuania, and Estonia