How is the active cell indicated on the Excel sheet?

Here, the correct answer is The dark wide border.

Neither a dotted border or a blinking border is used to identify the active cell in an excel worksheet because both can’t highlight any cell as the dark wide border does.

Here, the active cell is identified by a dark outline surrounding the wall. We can also call active cell as the current cell (or the cell which has a focus). And a group of active cells or current cells make an active sheet.

Although you can highlight multiple cells, but only one cell has the focus, for receiving input.