In 2000 Rents Were $18/SF and 10 Million SF of Space

In 2000 rents were $18/SF and 10 Million SF of space were occupied in a certain market. By 2006 12 Million SF of space were occupied, and rents were $19/SF, however, the CPI inflation) had increased more than 20 percent over this period. In this market, it appears that:

A) Demand is growing while supply is constrained.
B) Demand and supply are both growing at about the same rate.
C) Demand is either not growing, or not growing as fast as supply.
D) Demand increased in response to higher real rents.