A battery manufacturer wants to sell their batteries in boxes of 12 and cases of 24 boxes. You need to set up a unit group so that the manufacturer can sell different quantities. What should you create first? 

Answer options:

A. related unit
B. unit of measure
C. primary unit
D. base unit

C

Reference: https://docs.microsoft.com/en-us/dynamics365/sales-professional/create-unit-group-add-units