Which of the following providers do not have to accept assignment for a Medicare claim?

Parasympathetic innervation of the penile arteries that release ________ at their synaptic knobs causes the smooth muscle in the arterial walls to relax, resulting in erection

A) proglandastin B) luteinizing hormone C) nitric oxide D) gonadatropin-releasing hormone

The most obvious type of bleeding is caused by _______ wounds, also known as external wounds

Fill in the blank(s) with the appropriate word(s).