Scientists examined diamonds

Answer choices

1. A

   Too Strong: most3% picked this

   Most diamonds with higher-than-normal concentrations of sulfur-33 were formed at least 2.9

   We can never infer anything about "Most X's" unless we had a fact about "Most X's". We were never told anything about "most diamonds with higher concentrations of sulfur-33", so we can't derive that most diamonds with that trait came from this era. This trap answer is a variation of the classic "only thing mentioned ? only thing". Because the passage only mentions high sulfur diamonds forming 2.9 billion years ago, this answer wants to trap us into thinking "the only time high sulfur diamonds formed was 2.9 billion years ago".

   3%
2. B

   Unsupported Causal Relationship5% picked this

   Ultraviolet light causes the oxygen in Earth's atmosphere to react chemically

   We know that UV light stimulated some chemical reaction that led to the high-sulfur content of these diamonds. We have no way to say that this chemical reaction has anything to do with oxygen. This answer is just offering a Word Salad that invents a causal relationship between some of the wording in the last sentence and some of the wording from the previous sentences.

   5%
3. C

   Correct89% picked this

   Earth's atmosphere contained very little, if any, oxygen 2.9 billion

   Why this is right

   The final sentence tells us that, "If there was enough UV light to stimulate chemical reactions, then there was at most a trace a of oxygen in Earth's atmosphere 2.9 billion years ago." We know there was enough UV to stimulate chemical reactions, because we know that the high-sulfur diamonds were caused by chemical reactions stimulated by UV light. So we know that there was at most a trace of oxygen in Earth's atmosphere 2.9 billion years ago.

   Skill tested: Most Supported · how this choice captures the argument's function is the move to repeat next time.

   89%
4. D

   Too Strong: rarely1% picked this

   Sulfur-33 is rarely found in diamonds that were formed more recently than 2.9

   This essentially has the same problem as (A). Since the passage only mentioned sulfur-33 in diamonds that were formed 2.9 billion years ago, the test is trying to lure people into thinking "sulfur-33 only appeared in diamonds that were formed 2.9 billion years ago, so it rarely appears in diamonds since then". For all we know, all diamonds ever have sulfur-33 in them. The passage only told us that there are some diamonds from 2.9 billions years ago with more sulfur-33 than usual.

   1%
5. E

   Too Strong: only2% picked this

   The formation of diamonds occurs only in the presence of

   The passage doesn't give us any harsh rule that says "diamonds only form under this condition". It said "higher than normal concentrations of sulfur-33 only occur when chemical reactions are stimulated by UV light".

   2%