Answer:
Cheese and Bun
Step-by-step explanation:
Bun and cheese have more carbs than the other components of the hamburger. Bread has a lot of carbohydrates that are part of starch. Cheese also has some carbohydrates from milk, such as lactose.
Onions also have a certain amount of carbohydrates, but in a very small amount compared to previous ingredients.
Meat sometimes have products derived from starch or other meat-binding compounds, but they do not have a significant amount of carbohydrates.