Official Explanation
Conclusion: This will drive up the cost of producing orange juice and thus push up the price of orange juice for the consumer.
Premise: Because of a recent drought in Florida during the orange-growing season, the price of Florida oranges this season will be three times the usual price.
Assumptions: There’s no other way to interpret the facts. Because a recent drought is making Florida oranges cost three times the usual price this season, the cost of producing orange juice will go up and thus push up the price of orange juice for the consumer. There is no other explanation.
The question stem asks which answer choice most seriously weakens the argument, so this is a weaken question. The argument uses an interpretation of evidence reasoning pattern, which can be identified by the presentation of specific facts as evidence. In this case, that the price of Florida oranges this season will be three times the usual because of a recent drought, which in turn will drive up the cost of producing orange juice and push up the price for the consumer.
The standard assumption of an interpretation of evidence reasoning pattern is that there is no other way to interpret the facts. Because this is a weaken question, the correct answer will demonstrate that the facts do not necessarily lead to the conclusion. In other words, that just because the price of Florida oranges this season will be three times the usual price because of a recent drought, that will not necessarily drive up the cost of producing orange juice and push up the price for the consumer. Evaluate the answer choices, looking for one that matches this idea.
Choice A: No. This answer choice is out of scope. Even if The recent drought was not as severe as predicted, it could still have enough impact to drive up the cost of producing orange juice and push up the price for the consumer.
Choice B: Correct. This choice weakens the argument. If Only a small percentage of the oranges used to make orange juice are grown in Florida, then just because the price of Florida oranges will be three times the usual would not necessarily drive up the cost of producing orange juice and the price of orange juice for the consumer in general.
Choice C: No. This answer choice is out of scope. Even if Other ingredients are used in the production of orange juice, the price of Florida oranges this season (which are) three times the usual price could still have enough impact to drive up the cost of producing orange juice and push up the price for the consumer.
Choice D: No. This answer choice is out of scope. Even if Last year the price of oranges was lower than the average over the past ten years, the price of Florida oranges this season (which are) three times the usual price could still have enough impact to drive up the cost of producing orange juice and push up the price for the consumer.
Choice E: No. This answer choice is out of scope. An eventual price of oranges has no impact on the price of Florida oranges this season.
The correct answer is choice B.
Hope it helps