Why are certain atmospheric products like TPW, CLW, and surface wind speed only retrieved over ocean surfaces? (Click the button for the best answer below.)

a) The microwave signal over land is contaminated by diurnal temperature changes, making retrieval impractical. b) Retrieval of these products depends upon the changing surface roughness of the ocean. c) These products are heavily influenced by varying and largely unknown amounts of soil moisture, making retrieval impractical over land. d) The surface wind speed product depends upon ocean surface roughness and retrieval of TPW and CLW over land is impractical due to large emissivities/brightness temperatures that mask the cloud water and water vapor signals.