The Habit Burger Grill is considering adding breakfast items to their menu. First, they want to determine how many people visit other restaurants for breakfast in the markets they serve. The management team selects two representative markets and hires groups of marketing students from the local universities. Their task is to visit the various restaurants and keep a tally of the number of people who dine in the restaurant and/or order from the drive-through window during a one-week period between the hours of 6 a.m. and 10 a.m. Which method of data collection are the students using? a. Observation b. Interpretive research c. Survey research d. Personal interviews