6) (7 points) Arsenic is a potential groundwater contaminant. Based on a typical adult female ingesting the water under EPA-recommended exposure factors throughout the lifespan, calculate lifetime cancer risk for each of the following scenarios: (1) to drink unchlorinated groundwater with 15 ppb of arsenic, or (2) to switch to a surface water supply that has no arsenic, but as a result of chlorination, instead has a chloroform concentration of 60 ppb? Which option will result in the greatest lifetime cancer risk