Which of the following statements about the demand space curve are true?

A、The spatial change of demand space curve can reflect the structure of retail location space in the city to some extent.;
B、The demand space curve changes gently, which reflects that retail location has a
strong spatial agglomeration.;
C、If the demand space curve changes steeply, the retail location tends to disperse.;
D、Demand space curve is independent of retail location.