Final answer:
The best absorbed iron sources are foods high in heme iron, which is found in animal sources like sirloin steak. Kidney beans, cheese, and broccoli are also good sources of iron, but they contain non-heme iron which is not as well absorbed by the body.
Step-by-step explanation:
The best absorbed iron sources are found in foods high in heme iron, which is absorbed more efficiently than non-heme iron. Non-heme iron is found in plant foods, while heme iron is found in animal foods.
Based on the list of foods provided, the best absorbed iron source would be sirloin steak as it is a type of red meat that contains heme iron.
Kidney beans, cheese, and broccoli are also good sources of iron, but they contain non-heme iron which is not as well absorbed by the body as heme iron.