What is illustrated by the majority of water-transfer projects? 

A)  the principle that you cannot do just one thing 
B)  the concept of ecological succession 
C)  the tragedy of the commons 
D)  the climate-biome principle

Water-Transfer Projects

Large-scale engineering projects that aim to move water from one geographical location to another to address water scarcity issues.

Ecological Succession

The process by which the structure of a biological community evolves over time, involving species replacements and biodiversity changes.

Tragedy

A lamentable, dreadful, or fatal event or affair; often a situation involving great loss and misfortune.