Which of the Following Is NOT a Good Example of the Observation

Multiple Choice

Which of the following is NOT a good example of the observation method of marketing research?

A) The manager of a supermarket occasionally walks through the store to see what customers are doing.
B) A drugstore installs optical scanners at its checkout counters.
C) The owner of a shopping center puts a counting device at the entrance to count how many cars come in.
D) A store manager studies videotapes of consumers shopping in the store.