Asthma prevalence is on the rise in Arizona. A recent cross-sectional study among a group of 160 grade school boys found that 64 per 100 (45 of 70) of grade school boys living near Speedway were asthmatic compared with 17 per 100 (15 of 90) who lived further. The researchers attributed this increase prevalence of Asthma to exposure to car exhaust by proximity to Speedway. The Relative Risk of Asthma for those exposed to Speedway is:a- (15/90) / (45/70) = 0.26b- (15/160) / (45/160) = 0.33c- (45/160) / (15/160) = 3d- (45/70) / (15/90) = 3.86e- There is not enough information to calculate this rate.