Answer:
D. product line
Step-by-step explanation:
Based on the information provided within the question it can be said that the large variety of yogurts sold by the Dunchen brand is collectively an example of a product line. This term refers to a group of similar products that a company releases and markets under the same brand name. Which is what all the yogurts that they sell are, while each individual type of yogurt would be a Product Item.