Final answer:
Option c. A French drain uses a trench, gravel, and dry cement to effectively transport water away from a building's foundation, preventing potential structural damage caused by water accumulation.
Step-by-step explanation:
The construction technique that uses a combination of a trench, gravel, and dry cement to transport water away from a foundation is known as a French drain. This system is designed to prevent water from pooling around a building's foundation, which can lead to structural damage over time.
The trench is dug around the perimeter of the foundation, then filled with gravel and a perforated pipe is often placed at the bottom to collect and redirect water. A layer of dry cement, also referred to as filter fabric, is then typically added on top of the gravel to prevent soil from clogging the system, ensuring a more effective water flow away from the foundation.