To determine which graph represents a proportional relationship, we need to understand that a proportional relationship is a linear relationship that passes through the origin $(0, 0)$. This is because the equation of a proportional relationship is $y = kx$, where $k$ is the constant of proportionality.

Analysis of the Graphs:

1. Graph A: The line does not pass through the origin, so it does not represent a proportional relationship.
2. Graph B: The line passes through the origin and is straight, meaning it represents a proportional relationship.
3. Graph C: The line does not pass through the origin, so it does not represent a proportional relationship.

Conclusion:

Graph B represents a proportional relationship because it passes through the origin.

Would you like further clarification or additional help?

Here are five related questions:

1. What is the importance of the constant of proportionality in proportional relationships?
2. Can proportional relationships have negative slopes?
3. How do proportional relationships differ from linear relationships in general?
4. What are some real-world examples of proportional relationships?
5. How can you determine the constant of proportionality from a graph?

Tip: Always check whether the line passes through the origin when determining if a relationship is proportional!