Law of demand shows relation between

Income and price of commodity
Price and quantity of commodity
Income and quantity demanded
Quantity demanded and quantity supplied

The correct answer is: B. Price and quantity of commodity.

The law of demand states that, all other things being equal, the higher the price of a good, the less people will demand that good. Conversely, the lower the price of a good, the more people will demand that good.

Income and quantity demanded are not directly related. A change in income can affect demand for a good, but it does not necessarily do so in a predictable way. For example, if people have more money, they may demand more of some goods and less of others.

Quantity demanded and quantity supplied are also not directly related. Quantity demanded is the amount of a good that consumers are willing and able to buy at a given price. Quantity supplied is the amount of a good that producers are willing and able to sell at a given price. The law of demand and the law of supply are two different economic laws that describe how these two quantities are related.