When analyzing the housing market, the supply curve
a. will be upward sloping because the higher the price of a house the more that will exist
b. will be horizontal to illustrate that the supply of housing is a stock variable
c. will be downward sloping; that is what went wrong with the housing market
d. will be vertical to illustrate that the supply of housing is a stock variable
e. could be horizontal, vertical or upward sloping depending upon the housing market in question