Which is more economical: purchasing the economy size of a detergent at 6 kilograms for $6.15 or purchasing the regular size at 790 grams for 60? Select the correct choice below and fill in the answer box to complete your choice. (Round to two decimal places as needed.) OA. Purchasing the regular size is more economical because the regular size costs $ less per kilogram. B. Purchasing the economy size is more economical because the economy size less per kilogram. costs $