What is a prediction?

a guess about what will happen as a consequence of something else
a retest of experimental results to make them reliable
background research completed with questioning
a conclusion derived from evidence and logical reasoning

According to the passage, which of these is true about gray water systems? a) gray water systems use plants that require less water. eliminate b) gray water systems require the use of less fossil fuels. c) gray water systems reduce the amount of fresh water used. d) gray water systems reduce the amount water used by shower heads.