Why Have the Iowa Caucus and New Hampshire Primary Played

Why have the Iowa caucus and New Hampshire primary played such an important role in the presidential nomination process?

A) Many delegates are at stake in each race.
B) The two states are so much like the nation as a whole that a candidate who does well there will do well nationwide.
C) They receive a great deal of media attention because they are the first major events of the presidential nomination.
D) They are late in the presidential nominating process.
E) Most candidates are from one of these two states.