Which of the following describes the relationship between economic collusion and the effect on the GDP?

Collusion results in an increase in competition, negatively affecting the GDP. 
Collusion results in a decrease in competition, positively affecting the GDP. 
Collusion results in a decrease in competition, negatively affecting the GDP
Collusion results in a decrease in competition, negatively affecting the GDP. 

Collusion results in a decrease in competition, negatively affecting the GDP.