Answer:

To activate a cell in a spreadsheet, such as in Microsoft Excel or Google Sheets, you have multiple options. These options are pressing the Tab key, clicking the cell, or pressing an arrow key.

Pressing the Tab key:
- Pressing the Tab key is a quick and efficient way to move from one cell to another in a spreadsheet.
- When you press the Tab key, it moves the cursor to the next cell in the same row.
- This action activates the new cell by selecting it and allowing you to enter or edit data.

Clicking the cell:
- You can activate a cell by simply clicking on it with your mouse pointer.
- When you click on a cell, it becomes the active cell, and its contents are displayed in the formula bar or input box.
- Clicking on a cell also allows you to enter or edit data directly in that cell.

Pressing an arrow key:
- Another way to activate a cell is by using the arrow keys on your keyboard.
- When you press an arrow key (up, down, left, or right), it moves the cursor to the adjacent cell in that direction.
- This action activates the new cell, and you can start entering or editing data in that cell.

All of the above:
- The correct answer to this question is option 'D' - all of the above.
- This means that you can use any of the mentioned methods (pressing the Tab key, clicking the cell, or pressing an arrow key) to activate a cell in a spreadsheet.
- Each method serves the same purpose of selecting and making a cell active, allowing you to perform various operations on it.

In conclusion, activating a cell in a spreadsheet can be done by pressing the Tab key, clicking the cell, or pressing an arrow key. These options provide flexibility and ease of use when navigating and inputting data in a spreadsheet program.