Answer:
All except 'a' i.e The price of a can of beans
Explanation:
Demand Curve is the graphical representation of quantities of a good demanded at different prices, other factors remaining constant (ceteris paribus).
The curve is downward sloping due to inverse relationship between price & quantity demanded, as per law of demand. Change in price defines quantity demanded movement on the curve itself. Any change in factors other than price shifts the curve altogether.
In this case : Determining demand curve of 'Canned Beans' - would be based only on relationship between their quantity demanded & their own i.e canned beans price. All other factors - tomato can price, their cost of production, their supply are held constant as per 'ceteris paribus'.
