Which of the following is a disease characterized by hyperactive sebaceous glands and often associated with dandruff?

A 30-year-old Caucasian male with HIV/AIDS develops right-sided weakness involving his right leg. A MRI of his brain reveals multiple ring enhancing lesions within the white matter in his left frontal lobe. The most likely source of this infection in the United States is

A patient presents to a physician with jaundice. Physical examination reveals a nodular, enlarged liver. CT of the abdomen shows a cirrhotic liver with a large mass. CT-guided biopsy of the mass demonstrates a malignant tumor derived from hepatic parenchymal cells. Infection with which of the following viruses would most likely be directly related to the development of this tumor?

Following the rule of nines, what percent would a third degree burn to the entire arm and back cover? 

A 68-year-old man sustains a myocardial infarct resulting from thrombotic occlusion at the origin of the left circumflex artery. Cardiac catheterization demonstrates that the patient has a left dominant coronary circulation. In which of the following areas of the heart has ischemic necrosis most likely occurred?