Which of the following functions returns the current date and time?

The function that returns the current date and time is the NOW function. This function is specifically designed to provide both the current date and the time at which the function is called. When you use the NOW function in a spreadsheet application, it continuously updates to reflect real-time information about the current date and time each time the worksheet recalculates. This makes it particularly useful for tasks that require the most up-to-date timestamp.

In contrast, other functions like TODAY only return the current date without the time component. The functions CURRENT and DATETIME do not exist in typical spreadsheet applications, which is why they would not be appropriate answers. Therefore, the NOW function is the correct choice when you're looking to capture the full current date and time.