In Ulrich's (1984)"room with a View" Study, What Was the Independent

Multiple Choice

In Ulrich's (1984) "room with a view" study, what was the independent variable?

A) whether recovering patients saw trees or a brick wall when looking out their windows
B) whether recovering patients had a room with a window or not
C) whether or not patients requested pain medication
D) from nursing records, whether or not nurses liked the patients