Scientists are discussing ways to remove excess carbon dioxide from the atmosphere by increasing the amount that is absorbed by plant life. One plan to accomplish this is to establish giant floating seaweed farms in the oceans. When the seaweed plants die, they will be disposed of by being burned for fuel. 


Which of the following, if true, would indicate the most serious weakness in the plan above? 


(A) Some areas of ocean in the Southern Hemisphere do not contain sufficient nutrients to support large seaweed farms.


(B) When a seaweed plant is burned, it releases an amount of carbon dioxide comparable to the amount it has absorbed in its lifetime.


(C) Even if seaweed farms prove effective, some people will be reluctant to switch to this new fuel.


(D) Each year about seven billion tons of carbon dioxide are released into the atmosphere but only about five billion tons are absorbed by plant life.


(E) Seaweed farms would make more money by farming seaweed to sell as nutritional supplements than by farming seaweed to sell as fuel.


Let’s look at the stimulus given-


Scientists are discussing ways to remove excess carbon dioxide from the atmosphere by increasing the amount that is absorbed by plant life.


Plan-

One plan to accomplish this is to establish giant floating seaweed farms in the oceans.


When the seaweed plants die, they will be disposed of by being burned for fuel. 


We need to look for an option that weakens the plan.


(A) Some areas of ocean in the Southern Hemisphere do not contain sufficient nutrients to support large seaweed farms.


Some areas of ocean in the Southern Hemisphere do not contain sufficient nutrients. This does not impact the plan as it is only talking about a relatively small area. As long as large areas contain sufficient nutrients to support the large seaweed farms, the plan is likely to succeed. This does not indicate any weakness in the plan. Eliminate


(B) When a seaweed plant is burned, it releases an amount of carbon dioxide comparable to the amount it has absorbed in its lifetime.


The plan is to grow seaweed plants to remove excess carbon dioxide from the atmosphere and to burn seaweed plants after they die.

Option B says that seaweed plants releases an amount of carbon dioxide similar to the amount it has absorbed in its lifetime.

If that’s the case, growing seaweed plants to remove excess carbon dioxide will not make any sense. B points out a weakness in the plan and is correct.


(C) Even if seaweed farms prove effective, some people will be reluctant to switch to this new fuel.

The question is whether they will be effective to solve the problem in hand. People being reluctant to use is beyond the scope of the argument. Eliminate.


(D) Each year about seven billion tons of carbon dioxide are released into the atmosphere but only about five billion tons are absorbed by plant life.

Option D only provides all the more reason to support the plan. Eliminate


(E) Seaweed farms would make more money by farming seaweed to sell as nutritional supplements than by farming seaweed to sell as fuel.


Making money is beyond the scope of the argument. Eliminate