I'm unable to view images, including scatterplots. However, you can determine the height in microns of the plant cells after 2.5 seconds by locating the corresponding point on the x-axis (2.5 seconds) and checking the height on the y-axis.
To help you further, it might be useful to describe the scatterplot to me or provide the coordinates for the points. If you know the approximate height at 2.5 seconds based on the scatterplot, you can choose the correct option from the ones provided.