One of the Disadvantages of Active Solar Energy Is the Requirement

One of the disadvantages of active solar energy is the requirement of extensive surface area to collect the solar radiation. One way to overcome this is to take advantage of existing surfaces. Which of these would be an unlikely place to install solar panels?

A) Roofs of buildings
B) Unproductive land in the desert
C) Subway tunnels
D) Strips of land along roadways
E) Capped landfills