Read the opening to Homer's The Iliad.
Sing, O goddess, the anger of Achilles son of Peleus, that
brought countless ills upon the Achaeans. Many a brave
soul did it send hurrying down to Hades, and many a hero
did it yield a prey to dogs and vultures, for so were the
counsels of Jove fulfilled from the day on which the son of
Atreus, king of men, and great Achilles, first fell out with
one another.
Which theme is the author most likely to develop in this work of literature?
O
A. The suffering endured by those cast into Hades
O
B. The falling out between Achilles and the son of Atreus
O
C. The consequences of petty and avoidable disputes
O
D. The responsibility, and ultimately the cost, of leadership

The answer is: letter B, The falling out between Achilles and the son of Atreus.

Explanation:

The conflict that happened between "Achilles" and "Agamemnon" (the son of Atreus) boils down to a woman named "Briseis." Briseis was a concubine war prize for Achilles after the Trojan war. In the story of Iliad, Agamemnon was forced by Apollo to give up Chryseis (Agamemnon's slave). As a reward to giving up her slave, he demanded that Briseis should be rewarded to him. This angered Achilles because Agamemnon was stripping him of his reward. Thus,  this caused a war between them that killed many lives.

Clearly, the opening to Homer's Iliad shows the falling out between Achilles and Agamemnon (the son of Atreus).