Which of the Follow Would Tend to Reduce the Bargaining

Short Answer

Which of the follow would tend to reduce the bargaining power of buyers?
a. Large number of buyers.
b. Products of the industry do not produce clear cost advantages or enhance the quality of life for buyers.
c. Purchase standard, undifferentiated commodity products from suppliers.
d. Willingness and ability of buyers to integrate backward.
e. All of the above.