nightblade354 wrote:
Eight large craters run in a long straight line across a geographical region. Although some of the craters contain rocks that have undergone high-pressure shocks characteristic of meteorites slamming into Earth, these shocks could also have been caused by extreme volcanic events. Because of the linearity of the craters, it is very unlikely that some of them were caused by meteorites. Thus, since the craters are all different ages, they were probably caused by volcanic events rather than meteorites.
Which one of the following statements, if true, would most strengthen the argument?
(A) A similar but shorter line of craters that are all the same age is known to have been caused by volcanic activity
(B) No known natural causes would likely account for eight meteorite craters of different ages forming a straight line
(C) There is no independent evidence of either meteorites or volcanic activity in the region where the craters are located
(D) There is no independent evidence of a volcanic event strong enough to have created the high-pressure shocks that are characteristic of meteorites slamming into Earth
(E) No known single meteor shower has created exactly eight impact craters that form a straight line
Passage Analysis
Eight large craters run in a long straight line across a geographical region.
Eight huge pits formed out of some huge impact are present along a straight line in a particular region of the earthAlthough some of the craters contain rocks that have undergone high-pressure shocks characteristic of meteorites slamming into Earth,
One or more of these craters contain rocks whose properties point to a reason of origin as meteorite impact.Still... these shocks could also have been caused by extreme volcanic events.
It is also possible that extreme volcanic eruptions led to these formations as well.Because of the linearity of the craters, it is very unlikely that some of them were caused by meteorites.
The chance that one or more of the craters are formed by meteorite impact is extremely low considering that they are placed in an exact straight line.Thus, since the craters are all different ages,
Also, considering that these craters were formed in different time periods,they were probably caused by volcanic events rather than meteorites.
The author concludes that the actual reason of formation of this geographical feature are volcanos, not meteorites. Question Stem: Which one of the following statements, if true, would most strengthen the argument?
Direct strengthener question
Thought process
The strengthener framework should ask
What new information will make us believe more in the conclusion that the line of craters was formed by volcanos and not meteorites
Given that
they are placed in a straight line but were formed in different ages.
Possible strengtheners:Any information that tells us that volcanic eruptions can happen along a straight line.
Any information that tells us so many meteorite craters forming a line is extremely unlikely.
Any information that denies a combination of meteors and volcanoes together leading to the formation.
Option Analysis
(A) A similar but shorter line of craters that are all the same age is known to have been caused by volcanic activity
Craters formed during the same period are not similar to the case in hand. Hence this option is irrelevant.(B) No known natural causes would likely account for eight meteorite craters of different ages forming a straight lineThis option increases our belief in the conclusion that meteorites did not lead to the crater line. This is in line with the second type of strengthener mentioned. Hence a correct answer(C) There is no independent evidence of either meteorites or volcanic activity in the region where the craters are located
Denies the cause we want to support as well. Cannot be the correct answer.(D) There is no independent evidence of a volcanic event strong enough to have created the high-pressure shocks that are characteristic of meteorites slamming into Earth
Against the hypothesis supported by the conclusion. Hence not a strengthener.(E) No known single meteor shower has created exactly eight impact craters that form a straight line
Not relevant because, like option A, it talks about only craters formed during the same time period.Answer is B.Thansk for the explanation, but isn't volcanic eruption a natural cause.
In B if meteorites are ruled out so the volcanic eruptions may also be ruled out.