Moses is best known for which biblical event?

Moses is best known for the event of parting the Red Sea, which is a pivotal moment in the biblical narrative found in the Book of Exodus. This event signifies Moses’ role as a leader and prophet who guides the Israelites out of slavery in Egypt. The miraculous parting of the Red Sea allows the Israelites to escape from the pursuing Egyptian army, demonstrating divine intervention and the power of faith. This act not only illustrates Moses' extraordinary relationship with God but also serves as a powerful symbol of liberation and deliverance in many religious traditions.

The other options do not accurately represent Moses' actions: building an ark pertains to Noah, battling giants relates to David, and leading the Trojans does not reference any biblical figure, as this is related to the mythology of ancient Greece, particularly the Trojan War. Thus, option A is clearly the event most closely associated with Moses.