Final answer:
The statement that best justifies the conclusion is option c) If two lines intersect, then their intersection is exactly one point.
Step-by-step explanation:
The statement that best justifies the conclusion is c) If two lines intersect, then their intersection is exactly one point.
The given information states that X is the midpoint of line segment WY. This means that X is equidistant from both W and Y, making it the unique point of intersection between the two lines. the definition of a line segment and the definition of midpoint help in understanding the given conclusion, but they do not directly justify it. The substitution property is not relevant in this context. Therefore, option c) is the most appropriate statement to support the conclusion based on the given information.