Which one of the following is a cash-assistance program used to fight poverty in the United States?

If you travel to Mexico you will often see currency exchange businesses along the way as you approach the border

Even though each of these businesses is essentially "selling" the same product (i.e. Mexican pesos) how is it that some of them are able to charge more for the peso than others?

Cartels persist despite laws against them because

A) international cartels are legal. B) it is impossible to convict firms. C) of the Prisoners' Dilemma issue. D) All of the above.