In Rounding Off Numbers

Multiple Choice

In rounding off numbers:

A) when the digit next to the last one to be retained is less than 5, the last digit should be left unchanged.
B) when the digit next to the last one to be retained is greater than 5, the last digit is increased by 1.
C) if the additional digit is 5, the last digit reported is changed to the nearest even number.
D) follow all of the above.