City a Has a Population of People Who Are Exposed

City A has a population of people who are exposed to HIV, whereas City B has a population of people who are considered nonexposed to HIV. There were 3,267 new HIV cases in a given year for City A, with a population (exposed) of 10,000,000. There were only 5 new HIV cases in the same year for City B, with a population (nonexposed) of 150,000. Which is the attributable risk of HIV occurring in City A in terms of cases per 100,000 population?

A) 3.33
B) 13.55
C) 29.34
D) 32.67