This is a strengthen with sufficient premise question. Remember that asufficient premise is sufficient for a conclusion, if and only if the existence of the premise guarantees or brings about the existence of the conclusion. Therefore, we need to find the premise that 100% guarantees the conclusion. The way you want to attack these answer choices is two-pronged. Ask yourself, does it strengthen? If it doesn't, then cross it out and continue to the next answer choice. If it does strengthen, however, then ask yourself whether or not the premise guarantees the conclusion.
The environmentalist's conclusion is that the oil company's actions in cleaning the otters was not motivated by an environmental concern.
Why? The environmentalist cites the oil company representative's admission to the press that news photographs of oil-covered otters would be particularly damaging to their public image, which plays an important role in their level of sales--therefore, their real concern is their public image.
Answer choice (A) states: "oil company cannot have more than one motive for cleaning the otters affected by the oil spill."
Does this strengthen? Yes. This eliminates the possibility that the oil company could be both motivated by their concern for the environment and for their public image, which would break down the environmentalist's argument. Therefore, answer choice (A) strengthens the environmentalist's argument.
Does this guarantee the conclusion? Yes. If the oil company cannot have more than one motive for cleaning the otters, then their admissions to the press that the photographs of oil-covered otters would be particularly damaging to their public image, which plays an important role in their level of sales, is evidence of their motivation for up keeping their public image, which--according to answer choice (A)--can be their only motive. Thus, answer choice (A) guarantees the conclusion of the argument.
Hope that clears things up! Please let us know if you have any other questions.
CeciJanuary 18, 2019
why not E? it also seems to strengthen
MichelleRodJanuary 22, 2019
Thanks for your question @ceci
The environmentalist's conclusion is "You have no such concern." In other words, the environmentalist is drawing a conclusion about the oil company's real motives.
Answer choice E is about the success of the oil company's efforts. There is nothing in the question indicating that the success of the efforts are related to the oil company's motives. In fact there are many reasons why their efforts might have been most successful this time around, such as the development of more effective methods. The important thing is that, given the information presented, we don't know why their efforts were more successful this time around.
Since we cannot relate the success levels to the oil company's motives, E does not strengthen the environmentalist's conclusion.
Irene-VeraApril 20, 2019
Hi, I can see why A is the correct answer but I'm just I guess confused in the sense that I avoided choosing it because it seemed like a necessary answer where it would strengthen and if negated weekend. How would I know when not to confuse the two or when I can choose an answer like A. I know the test makers will try to confuse us with answer choices that are either one.
