Explanation: :
There are many factors that can influence the balance of power in a negotiation. These factors are classified into 3 levels:
Macro level: STEEPLE framework: social, technological, economic, environment, political, legal and ethical
Micro level: Porter's five forces:
Diagram
Description automatically generated
One-to-one buyer-supplier dynamics.
The question asks about the micro factors that increases supplier's bargaining power. Among 5 answers, only 2 are likely to increase buyer's power:
There are no close substitutes for rubber: the buyer has to buy rubber, not any other material.
Costs of changing suppliers are high: buyer entails a large barrier if they want to switch supplier.
Other answers cannot be correct because:
SRI sets up its own rubber plantation: Buyer secures its own supply
SRI's purchase amount makes significant proportion of supplier revenue: Suppliers are reliant on buyer. If the buyer stops buying from them, they can face serious cash flow problems
Rubber from different suppliers is virtually similar: undifferentiated product would shift the power balance towards buyer.