Answer to this question is option D i.e. unit price.
Explanation:
The unit price of the item can be understood as the price of a single product or one single commodity which forms a part of a group of items. When only one unit is to be sold then here comes the importance of 'unit price.' This is generally helpful in the retail sector where the products are bought in bulk after calculating the per-unit price of each commodity in that particular bulk.
