The Chapter Introduction Tells the Story of the First Battle

The chapter introduction tells the story of the first battle of Manassas (Bull Run) to make the point that

A) the Union army was unprepared to fight.
B) the Confederate army was unprepared to fight.
C) both sides underestimated what it would be like to fight a total war.
D) although the North had the advantage of initiative, the fighting would often turn out to be a series of Confederate victories against all odds.