The presence of water of Mars has been known for many years; its ice

Question

The presence of water of Mars has been known for many years; its ice caps are largely made of frozen water. Scientists reported recently that they had spotted widespread deposits of opals on the surface of Mars. Opals are minerals that require liquid water. Opal deposits lie in areas that appear to have been formed about two billion years ago.

Which of the following can be logically concluded from the above statements?

A. The planet must have had flowing water such as a river till recently.

B. The planet must have been warm enough for lakes and oceans for water during its initial years.

C. There is evidence for the possibility of life on Mars about two billion years ago.

D. Mars must have become hotter in the past one billion years drying up water on its surface.

E. Mars was hit by a meteorite two billion years ago

Nirmesh83 · Answer

IMO E

A incorrect No where passage talks about liquid water in present day.
B incorrect we don't know when was initial years 
C in correct
D incorrect

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winterschool · Answer

A. The planet must have had flowing water such as a river till recently.  Incorrect

cant say this from argument, recently found a opal deposit

B. The planet must have been warm enough for lakes and oceans for water during its initial years.  Correct

can say this from argument, opal required liquid water and it require two billion years to form

C. There is evidence for the possibility of life on Mars about two billion years ago.  Incorrect

dont know about life on mars

D. Mars must have become hotter in the past one billion years drying up water on its surface.  Incorrect

cant say this

E. Mars was hit by a meteorite two billion years ago  Incorrect

may be, but cant be a conclusion

sanjitscorps18 · Answer

A. The planet must have had flowing water such as a river till recently.
 Since the Opal deposits have been found recently and they require liquid water to exist

B. The planet must have been warm enough for lakes and oceans for water during its initial years.
 We don't know what the initial years of Mars are

C. There is evidence for the possibility of life on Mars about two billion years ago.
 Not discussed

D. Mars must have become hotter in the past one billion years drying up water on its surface.
 Not relevant

E. Mars was hit by a meteorite two billion years ago
 Not relevant

IMHO the answer should be A

Oppenheimer1945 · Answer

MartyMurray   KarishmaB

Can't we conclude C?

KarishmaB · Answer

No mention of possibility of life in the argument. We don't know what all is necessary for life. Water may be just one part of it. Life has not been mentioned anywhere in the argument and an inference brings in no new info so option (C) is not correct.

ShubhamA · Answer

Premise says that opal deposits require liquid water (on the surface of Mars). Mars ice caps are largely made of frozen water. Hence   Option D   could be right by stating that -- as Mars became hotter, its water bodies wiped out.
Please if anyone likes to shed some light.

Vinit800HBS · Answer

The argument mentions that Mars has ice caps that are frozen water. So, if the water bodies got wiped out because Mars became hotter, then we should not have ice caps present on Mars.

It is also possible that Mars became colder and the water bodies got frozen to for ice caps.

Hence, D is not logical.

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Invincible_147 · Answer

Pls explain why B is the answer as the passage doesnt provide any info about the initial years of mars, mars could be 10 billion years old.

DmitryFarberMPrep · Answer

You have a good point. This is a very poorly written question. For instance, "for lakes and oceans for water" doesn't make sense, and the statement that opals "require liquid water" is not precise enough for the GMAT. Require it for what?

Aside from when the "initial" years of Mars were, we also don't know that any liquid water on Mars must have formed lakes or oceans. Why not a river? This one needs to go.

Axwe7 · Answer

KarishmaB

I wouldn't necessarily say that having "oceans" and "lakes" is an inference that can be made. Liquid water, sure, but that could be present in droplets scattered across the surface as opposed to wide masses of liquid water. Hence, IMO, B) is out.

D) is also questionable since the passage says "two billion" while this option infers only for the past "one billion". However, given that water is now only present on the ice caps, and opals are scattered across the surface, it makes sense to infer the liquid water at one stage was also scattered across the surface, and whether it has all concentrated at the caps or has evaporated, are two possibilities. Since it's not directly inferable, D) is also out.

Not too sure on how to go about the answer here since I've eliminated other options, chose D) since "oceans" and "lakes" is too far a gap to bridge.

The presence of water of Mars has been known for many years; its ice

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