Having an Infant Share a Bed or at Least a Room

Having an infant share a bed or at least a room with parents is

A) a rare practice in most of the world's cultures.
B) more common in middle-income U.S. families.
C) associated with a desire to develop a closeness with one's infant as well as the ease of feeding and care giving.
D) positively correlated with the desire to build the infant's independence.