Atkinson Co. is analyzing the performance of its assembly line. Management observes that the line assembles 80 widgets per hour and that the total productive time needed to assemble one widget is 170 seconds. They works 8 hours in a day and assembly line currently has 6 stations. What is the efficiency of this line? a. 70-80% b. None of the given choices is correct. c. 81-90% d. less than 70% e. more than 90%