According to the last paragraph, the fourth way is "of a different kind" because(
[A] the first three ways can increase the water supply, while the fourth one can't
[B] the first three ways can make a better use of water, while the fourth one can't
[C] the first three ways is technology-based, while the fourth one is market-based
[D] the first three ways can't balance the supply and demand of water, while the fourth one can