Suppose There Are Only Five Construction Companies in a Particular

Suppose there are only five construction companies in a particular region that are each large enough to take on large public infrastructure projects (roads,bridges,sewers,etc.) .Representatives of these companies meet regularly for coffee or on the golf course and agree on which company will submit the lowest bid for a particular project.This type of firm behaviour is an example of

A) cooperative behaviour that results in higher output and lower prices.
B) cooperative behaviour that results in increased consumer welfare.
C) tacit collusion,and is legal as long as output is not restricted.
D) predatory pricing,and is meant to prevent new entrance to the industry.
E) explicit collusion and is illegal.