Neptune Inc., a cosmetics company, has come up with a new body wash. The marketing department of Neptune conducts market research to determine an appropriate price for the product. The representatives of the company go to various malls and sell the product at different prices. The sales volume for each price is measured, and they are compared to determine the optimal price. This is an example of: laboratory experimentation. a mail panel survey. a wireless phone survey. test marketing. a drop-off survey.