Based on your description of a line that moves diagonally upward from left to right on a coordinate plane, it suggests that as one variable increases, the other variable also increases. This indicates a positive correlation.
Since there are 25 closed points plotted along the entire length of the line, above, below, and on it, this suggests that the points conform fairly well to the general direction of the line, which indicates a strong relationship rather than a weak one.
Therefore, the best statement that describes the data illustrated in the graph is:
"The graph illustrates a strong positive correlation between the data."