Answer:
c. market competition would increase, decreasing profits.
Step-by-step explanation:
if people resell their old diamonds, then market competition would increase, decreasing profits. Introducing de beers old product into a market system will directly alter the sales of new products being developed by de beers. Their products has gained great trust among customers and even in the case of resales, a good number of needing customers would not mind as the value of Diamonds stays on the high side and this will affect market competition.