When Marriott Hotel Hires Someone to Book a Room at a Specific

Multiple Choice

When Marriott Hotel hires someone to book a room at a specific Marriott Hotel location in St.Louis and to pretend to be a customer,when,in fact,this "customer" is checking out the hotel and its staff on a performance survey,this is an example of a(n) :

A) an EEG study.
B) mystery shopper.
C) a natural situation.
D) a GSR study.
E) open observation.