Climatologists believe they know why Earth has
undergone a regular sequence of ice ages beginning
around 800,000 years ago. Calculations show that
Earth’s orbit around the Sun has fluctuations that
coincide with the ice-age cycles. The climatologists
hypothesize that when the fluctuations occur, Earth
passes through clouds of cosmic dust that enters the
atmosphere; the cosmic dust thereby dims the Sun,
resulting in an ice age. They concede, however, that
though cosmic dust clouds are common, the clouds
would have to be particularly dense in order to have
this effect.
Each of the following, if true, would lend support to the
climatologists’ hypothesis EXCEPT:
(A) Earth did not pass through clouds of cosmic
dust earlier than 800,000 years ago.
(B) Two large asteroids collided 800,000 years ago,
producing a tremendous amount of dense
cosmic dust that continues to orbit the Sun.
(C) Earth’s average temperature drops slightly
shortly after volcanic eruptions spew large
amounts of dust into Earth’s atmosphere.
(D) Large bits of cosmic rock periodically enter
Earth’s atmosphere, raising large amounts of
dust from Earth’s surface.
(E) Rare trace elements known to be prevalent in
cosmic debris have been discovered in layers
of sediment whose ages correspond very
closely to the occurrence of ice ages.

Hmmm.....not every CR is that easy
Think again!!

+1 kudos for the question

Guys think again. Question asks for the points that can "would lend support" to what has been stated in the argument.
(C) says Earth’s average temperature drops slightly shortly after volcanic eruptions spew large amounts of dust into Earth’s atmosphere.

So this is actually supporting the theory that due to dust(not cosmic) temperature has dropped(although slightly),leading to ice-age.

D is the option that does not strengthen the argument
D )Large bits of cosmic rock periodically enter
Earth’s atmosphere, raising large amounts of
dust from Earth’s surface.
Nothing has been mentioned abt the rise of dust from the earths surface and how it affects temperature on Earth.
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