Space heating through passive solar can be realized by _______. A. using overhangs that are used to shield the home from the high, summer sun, but are designed to allow the low, winter sunlight to enter the windows B. using building materials to absorb the sun's energy and store it, releasing it into the home at night after the sun has set C. using a flat-plate collector to absorb the sun's energy to heat the water. D. designing sunspaces and trombe walls