Answer:
Correct answer is D. Unpopular czar and royal family; replaced by democratic government first, then by Communists.'
Explanation:
Option A is not correct as Russia was had not president, but a czar as it was an Empire at the time.
Option B is not correct as Russia wasn't fighting in this war against China.
Option C is not correct as the sinking of Titanic had no connection whatsoever with the Russian revolution.
Option D is correct as after the czar was overthrown a new Provisional government was established, that was later replaced by the Bolsheviks.