Which of the following is an example of a field study?

Zack designed a maze to see how many tries it takes for a mouse to get from the beginning to end with no errors.

Chad has to create a study at home for his anthropology class and observes his sister and brother to see if males or females are more easily distracted.

A researcher creates a replica of a rat's natural environment to see if its sense of sight or smell is more beneficial when searching for food.

Xavier created a dining room and controlled the temperature, lighting, and distractions in order to see if certain meals triggered specific conversation topics.