The risk for real estate can be viewed as derived demand. If this is the case, the risk of real estate can be estimated from the underlying business it supports. Under this view, what would be the appropriate proxy to use for risk in the following types of real estate investments? 

a. Commercial real estate in New York. 

b. Commercial real estate in Houston. 

c. Commercial real estate in San Jose (Silicon Valley). 

d. Hotel complex in Orlando.