What does the command 'grid on' do in a MATLAB plot?

The command 'grid on' in a MATLAB plot serves to enhance the visualization of the plot by turning on the grid lines in the current axes. This means that when you invoke this command, horizontal and vertical grid lines are added to the plot, making it easier to read and interpret the data points relative to the axes.

When grid lines are activated, they aid in identifying the values of the plotted data more accurately as they provide a reference framework across the graph area. This is particularly useful in helping to visualize trends, patterns, or specific values in the data being represented, which ultimately leads to more effective data analysis and presentation.

In contrast, the other options do not accurately describe the function of the command. The 3D grid activation is not a feature of 'grid on', and it does not impact the scaling of axes or display data points. Instead, 'grid on' purely focuses on adding visual references in the form of grid lines to the existing plot.