Correct Answer: C
Explanation:
Recall that a ray is a line segment that has a vertex at one end and extends at the other. The extension is depicted by an arrow. In order for two rays to become one line segment the vertices must be connected and the arrows going in the opposite direction. For the rays to be going in the opposite direction they must have 180° angle between them.
Therefore, the correct answer is
"Connect the vertices of the rays and have their directions point 180° from each other."