Answer: A
Correct answer: 1,048,576
A worksheet holds 1,048,576 rows and 16,384 columns, running from A to XFD. Both figures are powers of two: \( 2^{20} \) rows and \( 2^{14} \) columns. The limits were raised with the .xlsx format in Excel 2007. The older .xls format held 65,536 rows and 256 columns, which is why the second option is offered - and why opening a large modern file in an old version truncates it. The shortcut Ctrl + Down Arrow jumps to the last row of a contiguous block, and from an empty column to the very bottom of the sheet, which is how the limit is seen directly. Ctrl + End goes to the last used cell - a figure that often exceeds the real data, because Excel remembers cells that once held content. These are limits of the grid, not of the practical size of a workbook: performance falls well before a million rows, and genuinely large data belongs in a database or in Power Pivot.