Final answer:
The A1 Thick & Hearty Burger was removed from the menu in 2015.
Step-by-step explanation:
The A1 Thick & Hearty Burger was retired from the menu in 2015. This decision often reflects changes in consumer preferences or a company's strategic planning regarding its menu offerings. It's not uncommon for fast-food chains to continually update their menu and retire items to make room for new ones.