I would say B) and D) apply to some of the differences between a Prime Minister and a President and also A). In addition, a Prime Minister is head of the government but may not be head of the state which may be a President in the same country or perhaps a Governor General.
Spain occupied many western lands in North and South America. EX1. North America: Florida and California were both occupied by the Spanish. EX2. South America: Mexico and other countries were occupied by the Spanish not all but a good bit were.
WW1 made Russia to leave during the war, so it was one of the factors that made them have a revolution