Final answer:
The highest sales tax rate per dollar can be found in Tennessee, which has a state sales tax rate of 7%. Among the mentioned counties, the highest sales price is likely to be found in Davidson County, which includes the city of Nashville. Therefore, the correct option is C.
Step-by-step explanation:
The highest sales tax rate per dollar can be found in Tennessee, which has a state sales tax rate of 7%. Among the mentioned counties, the highest sales price is likely to be found in Davidson County as it includes the city of Nashville which has a higher cost of living compared to smaller counties like Williams or Coffee. Additionally, Tennessee does not have a state income tax.