Which of the Following Would Lead to an Increase in the Demand

Which of the following would lead to an increase in the demand for rental apartments in your area?

A) a reduction in the rental price of apartments
B) a sharp increase in the number of out-of-town students attending the local college
C) an increase in the cost of the materials used to construct apartment units.
D) an increase in unemployment and reduction in the income of people in your area