RESTAURANT RESEARCH SCENARIO Insight Research, a Marketing Research Company, Has Been Hired by Been

RESTAURANT RESEARCH SCENARIO
Insight Research, a marketing research company, has been hired by a national chain of family restaurants to help them better understand their customers and how to serve them better. The restaurant chain has several competitors competing for the same type of customers and has experienced sales declines in the past few years. Researchers go "under cover" and pretend to be customers so that they will fit in while they observe the interactions between customers and the wait staff. Then they write a report of their interpretations of what they experienced personally while pretending to be a customer as well as what they saw regarding interactions of other customers with each other and with the employees of the restaurant. Some example conclusions drawn were that the employees were not especially attentive to the customers and that customers were overheard as saying they didn't intend to come back. Some researchers also noted that the food was not very good, and they saw several customers send orders back.
-Refer to Restaurant Research Scenario. Which of the following can be a criticism of the research approach used by Insight Research?

A) not providing useful information to the restaurant
B) results are objective
C) data are researcher dependent
D) presence of the researcher could have influenced the actions of consumers
E) interpretive research is not an acceptable approach for understanding consumer behavior