The water of the Krishna river in India is strictly controlled by the government. Crops along the river have a limited allocation that they are allowed to use for irrigation. But the trees that grow in narrow strips along the river’s banks also use its water. Clearly, therefore, if farmers were to remove those trees, more water would be available for crop irrigation.
Which of the following, if true, most seriously weakens the argument?
- The trees along the river’s banks shelter it from the sun and wind, thereby greatly reducing the amount of water lost through evaporation.
- Owners of crops along the river will probably not undertake the expense of cutting down trees along the banks unless they are granted a greater allocation of water in return.
- Many of the tree species currently found along the river’s banks are specifically adapted to growing in places where tree roots remain constantly wet.
- The strip of land where trees grow along the river’s banks would not be suitable for growing crops if the trees were removed.
- The distribution of water allocations for irrigation is intended to prevent crops farther upstream from using water needed by crops farther downstream.
Summary of the argument: The reasoning is clearly flawed – just by removing the trees, the author is assuming that the total amount of water available would suddenly increase. By stating that removing the trees along the river will not help the farmers will weaken the argument.
- This answer choice tells that the trees are actually beneficial for the farmers and it weakens the argument where the farmers want to remove the trees. Hence, this is the right answer.
- The argument already states that removing trees will provide more water for the crops, this information does not weaken the argument. Hence eliminated.
- This actually supports the argument because it states that these trees constantly have wet roots, so these trees probably consume more water than normal. Hence eliminated.
- We are not concerned about whether the land is prime for farming or not. Hence eliminated.
- These answer choice talks about the distribution of the total water, and not about whether the total water will increase or decrease once the trees are removed. Hence eliminated