$(4)$

When creating a crossbow for hunting, the design company added a protective piece by the trigger to prevent users for suffering cuts to their fingers when firing. This protective measure worked well for the first three years the item was sold. Unfortunately, three years into production the company switched suppliers and factory locations and someone forgot to ensure these protective pieces were added to the newly produced crossbows le$$elding to multiple customer injuries. This is an example of which of the following:

Design defect

Manufacturing defect

Failure to warn

Marketing defect