Final answer:
The ceteris paribus assumption is used to analyze the effect of changes in price on demand or supply, while holding other relevant factors constant. In this case, the price of the good, buyer income, and buyer preferences are all ceteris paribus variables. Therefore, all of these are ceteris paribus variables for demand.
Step-by-step explanation:
The ceteris paribus assumption is used to analyze the effect of changes in price on demand or supply, while holding other relevant factors constant. In this case, the price of the good, buyer income, and buyer preferences are all ceteris paribus variables. This means that when analyzing the effect of price on demand, we assume that buyer income and preferences remain unchanged. When any of these variables change, they can shift the demand curve for goods and services, causing a different quantity to be demanded at any given price. Therefore, all of these are ceteris paribus variables for demand.