Q4

[Noor-daoud]

can you explain how B is the correct answer from the rest ?
Thank you

[tommywallach]

Hey Noor,

This question is fairly general, so I'm just going to jump straight to the answer choices.

(A) "It is a fundamental tenet of geophysics that the Earth's magnetic field can exist in either of two polarity states..." (Line 1). This would mean that every geophysicist believes it, not just most.

(B) CORRECT. "...these reversals have been taking place at an increasing rate." (Line 8-9)

(C) For this, one needs to read through the whole third and fourth paragraphs. Basically, the two theories (heat-transfer hypothesis and asteroid-impact hypothesis) are never compared in terms of what would cause the reversal faster.

(D) This isn't supported by anything. We don't know when the heat-transfer hypothesis came about.

(E) This basically says that the heat-transfer hypothesis is FACTUALLY the thing that causes reversal. But it's just a hypothesis.

Hope that helps! In the future, try to say more in your posting. For example, discuss which answer choice you picked, and why it was tempting to you.

Good luck!

-t

[lsat2016]

Could you explain answer choice E?

Is it because the author outlines two explanations, and it would be considered WRONG to assume that the author is just supporting the second explanation?
Also, I was iffy with this answer choice as the passage says "friction and turbulence near the OUTER CORE-MANTLE BOUNDARY and initiating a reversal of the magnetic field" while the answer choice says "friction near the boundary of the INNER AND OUTER CORES brings on reversal of the polarity of the geomagnetic field". Could this be considered a wrong representation of the information in the passage?

Thanks!!