Which condition decreases supplier bargaining power?

The correct choice is that a product being easily substitutable decreases supplier bargaining power. This is because when there are multiple alternatives available for a product, buyers have more options to choose from, which diminishes a supplier's control over pricing and terms. In scenarios where substitutes exist, customers can shift their purchasing to different suppliers or products without much difficulty, thereby weakening the influence that any single supplier has.

In contrast, when there are no substitutes for a product, suppliers can maintain a stronger position, as customers have limited alternatives and are therefore more dependent on them. Similarly, if an industry is critically important to the supplier, it enhances their bargaining power, as they can leverage that significance in negotiations. Lastly, having few competitors increases supplier bargaining strength because it reduces the options available to buyers and can lead to a monopoly or oligopoly situation, allowing suppliers to dictate terms more effectively.