Answer: E.When there are so many industry rivals that the impact of any one company's actions is spread thinly across all industry members
Explanation:
The more the number of players in an industry the more it gets congested and especially for the competing sellers. The decision for increasing or reducing price is met by follower firms to do the same thing. It gets less competitive because you know all the players in the industry would be following the same practices and doing the same thing.