Answer
Ceteris Paribus says that only data from states B and E should be included on our demand curve.
Work Step by Step
In addition to the price of the vanity plate, factors that may impact demand are the price of alternative products (regular plates) and the consumer's income. In a demand curve these factors should be held constant, so the data from states B and E should be included since they have the same regular price and average income as our state.
