When creating a chart from a selection of cells, how does Excel

When creating a chart from a selection of cells, how does Excel
When creating a chart from a selection of cells, how does Excel decide what to put along the x-axis and what to put in the legend?

A. The data in the leftmost column goes along the x-axis and the remainder goes in the legend.
B. The labels along the top determine what is appropriate to place in the legend.
C. Whatever there are more examples of goes along the x-axis, and whatever there are fewer examples of goes in the legend.