Reading little fine print is important. Because when you signed up for your driver's license in Arizona you consented to having your blood, breath or urine sample taken and analyzed if a stopping officer has reasonable suspicion to believe you are driving under the influence. That is what is known as the implied consent law. By getting your license and driving on Arizona roads you have agreed to those terms. You have no say in which test is administered; that is completely up to the officer who stops you.