The graph provided shows an upward curving line. For a graph that rises from the left to the right, we would say it has a positive slope.
The slope of a graph indicates the relationship between the input variable (x-axis) and the output variable (y-axis).
As the x values increases, so does the y values. They both increase at a given rate (which is the slope of the line).
What we have in this question is a time-distance relationship.
The more time you spend, the more distance you'll cover, that is x increases, and so does y.