Kinger Burgers came out with a new hamburger and, before including it into its main menu, released it in two different cities with two different prices. The marketers at Kinger Burgers then analyzed the different levels of purchase made at these two different places, planning to using the information to help them set a nationwide price for the new offering. This is an example of ________.
A) ethnographic research
B) descriptive research
C) DIY research
D) experimental research
E) survey research
Answer: experimental research