The correct response that outlines the differences between a sales tax and a use tax is:
A sales tax is on the purchase of goods and services at the point of sale while a use tax is paid on goods and services purchased when sales tax was not paid.
This statement accurately describes that sales tax is collected at the time of purchase, while use tax is applied to items bought without sales tax, typically when purchased from out-of-state vendors or for items brought into a state where sales tax was not collected.