Final answer:
The style to apply a blue, accent 1 color bottom border to cells in spreadsheet software is generally a Thick single line style. This can be done in programs like Microsoft Excel under the Home tab by selecting Borders and customizing in the More Borders section.
Step-by-step explanation:
The style used to add a blue, accent 1 color, bottom border to the selected cells is not explicitly mentioned in the provided options. However, if we are referring to Microsoft Excel or a similar spreadsheet software where styles for borders are applied, then typically users are looking for a border that stands out against the content. To match the description which includes a blue, accent 1 color with a distinct line, users may often opt for a Thick single line style.
In Excel, for example, you can apply this style by selecting the cells, then going to the Home tab, choosing Borders, and selecting 'More Borders'. Within the Format Cells dialog, you can then choose the color, as well as the style, for the bottom border of the selected cells. Selecting a thick line option would prepare your table to have a strong, eye-catching blue line at the bottom of the chosen cells, which can be helpful for emphasizing data or separating sections in a spreadsheet.