Exam CBAP topic 1 question 309 discussion

A card printing solution is comprised of 4 stages: Loading, Printing, Packaging and Sorting. Loading and sorting of cards is done manually through operators, while printing and packaging are automated. The loading stage requires the operator to load 100 cards after an alarm is raised. Sorting requires an operator to distribute each package based on the printed address into the appropriate delivery box.
Which stage should be assessed as the most likely to increase process inefficiencies?