If you would like to re-read the material for a particular question, you can click on the link that is provided along with the correct answer. 1. Which of the following PDE-5 inhibitors has been associated with a risk of QT prolongation? A. Vardenafil (brand name Levitra) B. Avanafil (brand name Stendra) C. Sildenafil (brand name Viagra) D….