More common among friendly competitors than among bitter rivals,the undesirable consequences of tacit collusion often include oligopoly ,which harms consumers by raising prices above efficient levels

A .
B . Leading to undesirable consequences, and more common among friendly rivals than bitter enemies ,tacit collusion often include
C .Tacit Collusion,which is more common among friendly competitors than among bitter rivals ,leads to undesirable consequences ,often including
D. More common among friendly competitors than bitter rivals,tacit collusion leads to undesirable consequences,such as
E.More common among friendly competitors than bitter rivals,the undesirable consequences of tacit collusion are often including


Please explain