The correct answer to this open question is the following.
Although you did not attach the text or an excerpt of a lesson, we can comment on the following.
The concept of product modification can be explained this way. Companies have their products that are sold in a determined region. Let's say, the United States. However, when they expand and go to other countries, they need to adapt their products and services to the other countries where they are going to launch their products.
To be able to do that, companies have to do a lot of research to really understand the new culture, customs, ideas, and traditions, so companies like McDonald's can adjust, adapt or adequate their products and flavors to the people of South Africa, for instance. Some marketing experts called "tropicalize" a product to a specific region.
So in the case of South Africa, McDonald's had to understand how teh African people lived, what they like, what they enjoy, what their favorite flavors are, how spicy they like their food, what kind of condiments they accept, and so on. This will also allow executives of McDonald's to create special promotions, combos, and presentations of the food.