Final answer:
Whataburger started serving breakfast in all locations in 1980, expanding their menu to cater to early morning customers. Hence, option (A) is correct.
Step-by-step explanation:
The fast-food restaurant chain Whataburger began serving breakfast across all its locations in the year 1980. This introduction included their now-famous breakfast menu, which offers a variety of options including breakfast sandwiches and their iconic Honey Butter Chicken Biscuits.
The move to add breakfast items to their menu was aimed at satisfying customer demand for early morning dining options and has since become a staple aspect of Whataburger's service.