Final answer:
The DATEDIF function in Excel calculates the difference between dates using certain unit value options. One of the options provided is not a valid unit value for the function.
Step-by-step explanation:
The DATEDIF function is used to calculate the difference between two dates in Excel. The unit value options for DATEDIF are:
- Y: years
- M: months
- D: days
Therefore, the option that is NOT a valid unit value for the DATEDIF function is H (hours).