In the Book of Genesis, who killed his brother?

The correct response is based on the well-known biblical narrative in the Book of Genesis. The story describes how Cain and Abel, the two sons of Adam and Eve, made offerings to God. Cain, a farmer, brought fruits of the ground, while Abel, a shepherd, offered the best of his flock. God favored Abel's offering over Cain's, which led to Cain becoming angry and jealous. In a fit of rage, Cain confronted Abel in the field and ultimately killed him. This act of fratricide is significant in biblical literature as it illustrates themes of jealousy, sin, and the consequences of actions.

The other figures mentioned – Abel, Joseph, and Isaac – do not fit this specific narrative, as Abel is the victim of Cain's actions, while Joseph and Isaac are entirely separate characters within the Genesis narrative, each with their own distinct stories. Thus, the focus on Cain's actions makes him the correct answer regarding who killed his brother.