Concept:The Exodus began with the Passover, the final devastating plague in Egypt that caused Pharaoh to free the Israelites from slavery.
Explanation:God sent a series of plagues upon Egypt because Pharaoh refused to release the Israelites.
The tenth and last plague was the death of every firstborn child in Egypt.
God commanded the Israelites to mark their doorposts with the blood of a sacrificial lamb.
God "passed over" the homes of the Israelites, sparing their firstborn from death.
This saving event is known as the Passover.
When Pharaoh lost his own firstborn son, he urgently ordered the Israelites to leave Egypt.
That departure marked the beginning of the Exodus journey.
Later, during this same journey, God gave Moses the Ten Commandments at Mount Sinai.
The Last Supper was a New Testament event, while the crossing of the Jordan River and the building of the Ark came after the Exodus had already started.
Answer:A. Passover