Final answer:
Buyer bargaining power is moderate-to-weak when yoghurt products are highly differentiated, as this differentiation makes it difficult for consumers to substitute one brand for another simply based on price.
Step-by-step explanation:
Buyer bargaining power is considered moderate-to-weak in a scenario where yoghurt and products made from yogurt are highly differentiated by origin and by price. In this context, the presence of unique characteristics and brands creates a situation where buyers are less empowered to negotiate lower prices because they may develop preferences for certain types of yogurt. Differentiation effectively weakens the buyer's power by reducing the direct comparability of available products, thus making it harder for consumers to substitute one brand for another based on price alone. This is unlike a perfectly competitive market where products are undifferentiated and buyer bargaining power is stronger.