[solved] Which one of the following is not a factor that affects the strength of supplier bargaining power?

Whether it is difficult or costly for industry members to switch their purchases from one supplier to another or to switch to attractive substitute inputs.

Whether there are greater or fewer than ten suppliers of the item being purchased from suppliers

Whether industry members have sound business reasons to integrate backward into the business of suppliers and self-manufacture items they have been buying from suppliers

Whether suppliers provide an item that accounts for a sizable fraction of the costs of the industry's product

Whether the item being supplied is a commodity readily available from a host of suppliers or whether certain suppliers provide a differentiated input that enhances the performance or quality of the industry's product