Final answer:
Ground beef is the least likely to pose a choking risk for toddlers because it's easier to chew and swallow compared to nuts, popcorn, and round candy, which are known choking hazards.
Step-by-step explanation:
Among the listed options, ground beef is the food that is least likely to pose a choking risk for toddlers. This is because ground beef can be easily chewed and swallowed when cooked properly, compared to the other options which are hard or may conform to the shape of a child's throat. Nuts, popcorn, and round candy are all known choking hazards for toddlers due to their size, shape, and texture, which can easily block a young child's airway. It is important to supervise young children while eating and to avoid giving them high-risk foods.