The Textbook Notes That, "Using Naturalistic Observation, Researchers Found That

The textbook notes that, "using naturalistic observation, researchers found that women choose lower-calorie meals when eating with men than when eating with other women." The fact that the researchers used naturalistic observation means that:

A) they used random assignment and manipulated variables, such as whether women ate with men or with other women.
B) women were studied in everyday environments, such as cafes.
C) they gathered data mainly through questionnaires.
D) very few participants were studied.