Answer:
The answer is Price
Explanation with examples:
We define demand as the amount of some product that a consumer is willing and able to buy at a given price.
In addition to price, which is one of the most important factors, there are at least two other factors that affect demand.
Willingness to buy suggests desire, based on what economists call tastes and preferences. If you don't need or want something, you don't buy it.
Buying power indicates that income is important. Generally, teachers can afford better housing and transportation than students because they have more income.
The prices of related goods directly affect demand. For example, if you need a new car, the price of a Honda can affect your demand for a Ford.
Finally, the size and composition of the population can also affect demand. The more children a family has, the greater its demand for clothing. The more children of driving age a family has, the greater their demand for auto insurance, and baby food and milk.