Which of the following is a correct way to refer to the second cell in column A?

Referring to the second cell in column A is done using a specific format in spreadsheet applications like Excel or Google Sheets. The correct way is to combine the letter of the column with the number of the row, which in this case is "A2". This notation indicates that you are looking at the cell located at the intersection of column A and row 2.

The other formats provided do not adhere to the standard conventions used in spreadsheets. "2A" incorrectly places the number before the letter, which doesn't indicate a cell reference. "ColumnA2" suggests a label rather than a specific cell address. "A$2" is a mixed reference which locks the row reference while allowing the column reference to change; however, it still refers to the second cell in column A and is often used when copying formulas, but isn't the simplest form to state that particular cell. Hence, "A2" is the most straightforward and correct way to refer to the second cell in column A.