A) Popular military hero, and D) Economic and political chaos.
The French Revolution had involved much in France, and by the time Napoleon stepped into the picture, there was a desire for law and order and stability. He brought that as a military leader who was not afraid to fire "a whiff of grapeshot" (as one historian termed it) on royalist opponents in order to control and defeat them. ("Grapeshot" was Napoleon's use of cannons like shotguns to fire shrapnel at those opposing his troops.) By the time of that event, Napoleon had already established his military reputation against the British in the Battle of Toulon.
As to answer B, the Directory was weak, which allowed Napoleon to come to power. As to answer C), the Continental System was a policy enacted by Napoleon once he was in power.