The correct answer is D. All of the above.
An individual demand schedule shows the quantities of a commodity that an individual consumer is willing and able to purchase at different prices during a specified period of time, all other factors held constant. It is a tabular presentation of the law of demand, which states that, ceteris paribus, the quantity demanded of a good or service will decrease as the price of that good or service increases.
The individual demand schedule is a useful tool for understanding how consumers make decisions about what to buy. It can also be used to predict how consumers will respond to changes in prices. For example, if the price of a good decreases, the individual demand schedule will shift to the right, indicating that consumers will purchase more of the good at the lower price.
The individual demand schedule is a key concept in economics. It is used in a variety of economic models, including the theory of consumer behavior and the theory of the firm.