Based on your description of the line moving diagonally upward from left to right, it suggests a positive correlation. Since there are 25 closed points plotted along the line, above, below, and on it, it indicates that while there is a general trend, the points may vary in their exact positions relative to the line.
Thus, the best statement that describes the data illustrated in the graph would be:
The graph illustrates a strong positive correlation between the data.