Using the graph, we can see that the line passes through the origin, which is the point (0,0). The line also passes through the point (3,3), which means that the rise and run of the line is 3 units. Therefore, the slope (m) of the line is 3/3 or 1.
The equation of the line can be written as y = mx, where m is the slope. Substituting in the value of m, we get y = 1x.
Simplifying the numerical coefficient, we get y = x.
So, the correct equation for a line through the origin on the given graph is y = x.