Final answer:
According to Texas rules, unopened ketchup packets must be discarded after a customer has used them for hygiene reasons.
Step-by-step explanation:
According to Texas rules, unopened ketchup packets must be discarded after a customer has used them. Although items like salt or pepper packets can be saved and given to another customer if they were not contaminated, unopened condiment packets like ketchup should be discarded for hygiene reasons. Therefore, option a) Unopened ketchup packets must be discarded after a customer has used them.