For Studying Demand Relationships for a Proposed New Product That

For studying demand relationships for a proposed new product that no one has ever used before,what would be the best method to use?

A) ordinary least squares regression on historical data
B) market experiments,where the price is set differently in two markets
C) consumer surveys,where potential customers hear about the product and are asked their opinions
D) double log functional form regression model
E) all of the above are equally useful in this case