Rainwater from the roof is collected and funneled into a 25,000 gallon underground cistern . Wastewater from showers , sinks and toilets goes into underground purifying tanks and then into the cistern . The collected water then irrigates the land surrounding the house . Surrounding flowers and shrubs native to the area enable the property to blend into the surrounding rural landscape .
According to the above context, choose the best option to answer the following question.
Question: Why might this system have been designed ?
Options:
A. It is a source of alternative energy .
B. It is an attempt to create water .
C. It is an attempt at off - grid living .
D. It is a source of clean drinking water .


C