A．ccording 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